I started trying to keep my foreskin retracted around the age of 8, would not stay, but I kept at it. Finally around the age of 13 it stayed back all the time. Then only time, I would roll it forward, was if someone who knew I was not circumcised, was going to see me. Then I would cover for that brief period and then as soon as the showing was over, back it went.
I kept it that way for around 10 years, and it was back till the moment I had my penis circumcised. Never regregreted that decision. Still love my bare glans, sensitivity is still the same.