Much like toning muscle in the gym, a resting period between sessions can be beneficial (the muscle is allowed time to recoup and strengthen itself).
I find that when I take a rest from something, whether it be an instrument or another activity such as cooking or gardening, I find myself refreshed and "straightened out" if that makes any sense.
Sometimes I'll simply "forget" my technique, but it comes back. For me, clarinet is like riding a bike. Once you learn and practice enough, it sticks.
If I over work myself and try too hard, I get worse. (Tone the muscle too much, and it actually can get weaker, or you can pull it, cramp it, etc. I am not a fitness guru, just an example).