Found this on another forum. Credit to legonz

Q- What is one-itis?
A- One-itis is defined as an infatuation with another individual who does not return those same feelings. One-itis victims can usually be seen pining over a single individual, constantly overanalyzing every situation, and asking his friends what he can do "to get this girl". One-itis is generally seen a malady because the "relationship" in question does not produce similar feelings from all individuals involved.
Q- How do I get over my one-itis?
A- Women tend to get over a guy when she's away from him. Men, on the other hand, have intensified feelings about a girl when she's around. You know what this means, right? Do the girl ritual.
Step 1- Delete her number and name from her cell phone. If she calls, tell her you "have to do ---. I'll talk to you later."
Step 2- Rid yourself of any pictures of her. Throw them in a deep closet. You're only defeating yourself by keeping them around.
Step 3- Delete your e-mail transactions and her messager screenname, in addition to any online connections that you may reach her at. Don't block her. You don't hate her; you just don't care anymore. She is not a special vagina.
Step 4- Avoid places that she frequents for a period of time. If you work with her, that's your fault for getting involved with your fucking coworker.
Step 5-You're not angry at her; you're just moving on to bigger and better.
Step 6- Surround yourself with friends. Sarge immediately. NOW you position yourself to GFTOW.
Q- But she's special; she's different; she's perfect for me.
A- As of the last census, there are 6.5 billion people in the world. As the rough percentage of women is 53% of the total population, there are almost 3.5 billion women out there. Are you telling me that you just coincidentally tripped and fell into "the one"? There's a statistically higher chance of being struck by lightning three times than that being your "one special girl".
Q- Then why is she "perfect" for me?
A- Because males tend to rosetint and accentuate positive characteristics of women they feel they have a chance with. Try being critical of her one day. Notice how she doesn't shave her arms, or how she sports lovehandles, or has no common sense.
Q- Why do I feel that I have a chance?
A- She was either nice to you once or is still nice to you, but won't have sex with you because she likes feeling wanted. Thus, she likes having you around so that she can feel sexy, but she's not going to have sex with you. I've seen it work ONCE. ONE TIME. That's a single instance out of hundreds. Don't take the risk. Don't feed her ego and kick yourself in the balls day in and day out. Her bowel movements don't smell like lilacs. She's not special. You, on the other hand, are special, because when you realize that you can get ANY girl, one single girl means nothing to you.
Q- Why is one-itis bad?
A- Because a normal, healthy relationship consists of two (or more) individuals fulfilling each other and strengthening each individual. One-itis is one individual improving their confidence at the expense of another person. You can do better.
Q- How can I make sure I never get one-itis again?
A- Unlike what you would normally do in most situations (stop talking to women altogether), the goal here is to remain in contact with as many women as possible. This allows you to keep a "there's always more fish in the sea" perspective. Experience a lot of women, have sex with them if you choose, and attempt to hold a MLTR (multiple long term relationship). Try and balance two or three girls at the same time.
Q- So if I forget about her and move on, then I'll get her?
A- Get that out of your mind. Time and time again, I've seen buddies who only go after girls in hopes that the girl he's "forgotten" about will get jealous and chase him. Not gonna happen.
...and if it does happen, once you come around, she'll drop you again in seconds. Accept the inevitability that she has to be tossed aside.

^bump

this is an awesome post soemtimes i do get one-its but the best cureis to go out, for realzies

Great post... I have a roommate who gets serious one-itis. He had a friend who he was constantly fawning over and after a while he would tell her how he feels, she would deny him, then they wouldn't talk for a while. She would start texting him again and he would get wrapped up again, it's really sad.

Now I think he's over it, but the thing is that he gets one-itis for every girl he meets, even if he meets a girl at the club, he's constantly fixated on that one girl, and it's really annoying.

How can I get him to stop this, or change his ways, any thoughts?

I thought one-itis consisted of being infatuated by one woman, EVEN WHEN SHE RECIPROCATES. I.e. you're mad about this girl you've been dating/sleeping with and then start thinking she is 'the one'. One-itis will be sure to drive her away. Your post seems to imply that it's only one-itis if you're obsessed but she ain't interested??

One-itis is when her affections do not reciprocate the feelings you have towards her. No-one has a problem with a girl-friend or even meeting the so called "love of their life", there is nothing wrong with being completely infatuated with someone who shares the same feelings towards you. Thats a personal choice to fall in love with someone who loves you. One-itis is not a personal choice, but rather an overwhelming desire for this women who does not want you which causes a hang-up your game/life/time and if left untreated will lead to a dramatic lowering in ones' confidence in himself.

I had a bad case of one-itis in my last year of high school. It felt like we were meant to be together. But nope! Take the advice of the first poster and move on. Its good for you in the end.

Ok....i normally never ask for any advice but here goes. I had met this russian girl in the mall througha friend who quickly introduced me when i bumped into him. She works at one of those cellphone stand that just sells accesories. Anywho the first time i just wa slike hi becuase she was involved ina conversation with a friend of mines friend. We were just catching up and he asked me how i was doing and i was liek alright just looking for that russian girl i can't find. he says she is single but i didn't really think anything of it. Anyways about amonth later whih is now today i am with my cousin in the mall and i need a new attenae for my phone. Its actually oddly busy and the guy who works there helped me instead but she looked at me a few times, didn't really pay attention of how her interest looked. But i should of just time constrainted her by saying I am ina rush(which i was) and i really wanted to take you out sometime so could i have your number. So i dunno i got a case of one-ites and should of's.....next time i go into the mall you think its appropriate to just go in guns blazing with game?

Do what you feel will be healthy for you. Nobody can predict the outcome of your interaction with the Russian girl. I get over one-itis by simply looking to get rejected (I don't mean saying stupid things, but just gaming until things either go sour, or sweet.. It clears a whole lot off my chest when I do. There is nothing wrong for asking for help Brian. Absolutely nothing, I still ask for help. I always try and emphasize this, advice is worth a grain of salt, Experience is priceless, so go guns a blazing and if you get wounded head straight for the nearby shoe store to find your medic. game them, and have fun. So important to have fun, this is literally a fun game in which you deal with emotions.