One of the most effective motivation for me to start NoFap was the guilt of it after I was done fapping. I've completed 21 days today and I'm already feeling much alive than I was 21 days back. I'd always find a reason to fap, the smallest stimulations would get to my brain. Its like I've never wanted to stop fapping, it was more of a destination for me rather than a lifestyle. My last fap 21 days ago was a big realization that I've to stop it for good or else I'd be lost. Thanks to the nofap community for motivating me at times when I was on the verge of quitting. I haven't set any goal of a particular amount of days (90/120/150). I'd do it as long as I can.