I didn't do any flying during my 6 months of ground school. I put all my efforts into the books. A few did their night qualifications and others did the odd jolly. I probably could have found time if I had really wanted to go but to be honest I was completely focused on the ground school element. During my down time which was generally at weekends I would play sport, see friends etc, just got back into the real world for a day or two.
You may remember more than you expected the first time back up, especially with proper preparation. I would definitely recommend going up with an instructor if it's been some time between flights.
Good luck
Camel Toe
"Over Macho Grande?"