I’ve been doing PE for two and a half years now. Close to a six-moths-on, six-months-off routine. During my ‘on’ periods, I was able to gain a half an inch each time. I am on my third round now. During the ‘off’ periods I do anything from nothing to light jelqing in the shower (10-20 reps) and the occasional stretch.
I have found that during round 1, my gains came quick and stayed steady through the time period. Total PE period of gaining was probably 5 months here. Newbie gains.
My second round, I saw no gains for the first 2-3 months but then they came and continued until I hit my 1/2 inch goal. Total PE period about 7 months here.
Current round, I have seen just a hit of gains after about three months. Based on my previous experiences, I think I am close to a breakthrough. EQ is up and other indicators that I recognize from before.
So, I think you will have no problem getting back into it based on my experience. If you are out of the game long enough, you would hopefully even see “newbie” gains when you get back into it.