Started my CAA PPL in June 1988 at White Waltham (aged 19 years). Did 33 hrs, incl 4 hrs solo in PA28. Didn't do any more flying after April 1989.
Luckily I kept hold of my logbook.
Resumed flying with Tayside (C152) in June 2011. Progress was delayed initially as I was ready to go solo again within 5 hrs, but no Air Law.
Passed all exams first time. JAR PPL issued 29th Feb 2012.
My advice to those who resume flying after a long time out is to make a start on your Air Law asap. You will find that your ability to fly still exists, albeit a little bit rusty. Work like crazy and get all the remaining exams out of the way in good time. You don't want to sit exams on the same day as flying.