Many people join a tai chi school with lofty ambitions only to reach a rudimentary level of skill and simply remain there.
Remaining a beginner forever is pointless. No matter how much you learn it is still at the first level of skill. Years of practice don't mean anything if you're still a beginner. There's been no progress.
If you are sincere about trying to slow down the aging process, you're going to have to keep going. Don't stop at the beginning. Climb.