KGP,
This has already been covered to some extent. The concensus is fish learn fast to avoid recapture especially with the same lures. In fact it can be a problem in ponds as there are only so many fish and after awhile recapture becomes difficult.
Additonally some fish are faster learners than others just like people. I actually caught and released ths same bass twice once off of my pier within five minutes. I know this because of a conspicuous mark on the top of his head the other fish don't have. However this is the exception.
I can actually spook my bass that I feed daily by walking out onto the pier with a fishing pole in hand. It's really true! But my water is very clear.
However one thing that may be a factor in your lack of recapture is the spawning season. Once spawning commenses bass can be harder to catch as they are preoccupied. Procreation takes precedence over feeding sometimes to their demize, as in stress, which leads to reduced vitality and subsequent disease, and morbidity (sick fish).
