You're asking if it gets old only focusing on things the help improve your life, and as a result, positively progress your life in the direction you want it?
I guess it could get old, but it's a pretty safe rule of thumb to stick by.
Being unpredictable and striking back can also be fun for both parties though, then i think it's entirely applicable, I just don't see it in the OP's case.

So long story short I dated this girl for 3 years, like 6 months ago I broke up with her for unrelated reasons. She tried to get me back for like 5 months, I slept with her a few times for some easy pussy when she threw herself at me but never entertained the idea of getting back together.

So once she realized I wasnt taking her back, she got real personal and just tried to hurt my feelings. The only thing that actually made me mad was she told me that she cheated on me with one of my good friends (at the time) like a year and a half ago. I trusted her and I was faithful the whole time, but apparently she cheated on me and it pisses me off. Even more so that it was with one of my friends that I trusted. I asked him about it, he told me it was true and a bunch of other shit about how she lied and told him me and her broke up, got real hammered and he didnt even remember it happened until she told him..

But whatever, obviously i told him to fuck off and we wont be talking any more. I only needed to talk to him to confirm that it was true. Now that I know it is, I really, REALLY want to try to hurt my ex. She gave me SO much shit ALL the time about how I didnt try, when in reality she was just a stupid slut building a relationship on lies and being a whore.

So I am considering texting her this:

hey whats up? so i have spent some time with my phone records these last couple days, compiling this list of the exact dates and times you sent me texts in which you admit to some interesting things.. including but not limited to: smoking weed, drinking and driving, stealing from your parents, taking acid, taking shrooms, doing coke, being on xanax when you crashed your sable, abusing vicodin, abusing and selling your adderall (which im showing to your doctor too so kiss that script buh bye).. the list goes on. i hope your family knows about all that, cause as soon as im done theyre gonna find out. it's right on my phone records, so have fun trying to convince anyone that its a bunch of bs lol. your the worst kind of liar x, a disgusting cheater whore drug addict. i knew you were a huge slut when i fucked you the first time i met you, yet i trusted you anyway and you betrayed me. so im done helping you hide. its time for you to have no option but to be honest with everyone about what kind of person you are. fuck you slut have a good night


So what do you think, should I send it? I feel like i want to humiliate her, crush her feelings and ruin her life. i havent even STARTED to think about what i'm going to do with these 15 naked pictures i have of her, or the video of me fucking her in the ass and then cumming on her face.. But whatever i do with them, it will be fitting for the disgusting slut that she is. Can I get in trouble for this? We are both over 18 obviously, and i really want to hang it over her head.

Thanks for any insight

nice try??? hahaha, okay. I'm not sure what you mean by that.
I definitely wasn't assuming that a retaliation was out of ones control.
This is one of the very things that helps immensely with inner game, the ability to control your response and not react like an out of control dog.
So yes, i agree with you.

Go fuck her sister or her best friend or mum or something.

If someone screws me over big time I like a bit of revenge, just to even the score a bit, and as a warning not to mess with me again.

Don't go too far but, if I was you I'd just email the naked pictures of her to everyone you know and leave it at that.

what i "meant by that".....

was to call you out on your attempt to create a strawman argument by somehow linking definitively revenge with being out of control or unpredictable.

maybe that is how "you" associate revenge or retaliation, not all people are alike. you may not want to project your traits or perceptions onto the world (and everyone else) around as it may cause you to be narrow-minded and narrow-sighted.