Join the club and fly while you can!
Your skill retention will depend largely on how much time you get to fly before you take a break. Like riding a bicycle, if you only coasted down the driveway once, you won't have much skill to retain.
What do you have against instructors, anyway? They usually know about 1000 times more than you, and you might actually learn something by getting around them often. I've flown for over 20 years, and I still learn something nearly every time I go to the club field and get around the other fliers.

And memorize my signature. It's the truth.