I just finished a 2 week marathon. I rewarded myself by jerkin' it and holy fuck, it felt SO good and i cummed SO hard. I'm going for 3 weeks now and today is day 2, lol.
I forced myself to go 2 weeks recently to re-sensitize myself. It worked! Plus, since I quit smoking 3 weeks ago, I'm getting raging erections several times a day like I did when I was 20. It's awesome!!!