Subject: Do organisms learn, lose and then relearn lessons due to memory capacity?

I work at a fish hatchery,and I notice some things:  The fish don't seem to
learn from noxious stimuli.  They will learn it for the moment, perhaps, but the
next day, it they don't appear to have a memory of a bad experience.  

So, now I'm looking after some cats.  They appear to exhibit the same type of
behaviour:  They learn a lesson from being chastised (you can do this over and
over again {I'm sure you know}), and they will cease the non-desired behaviour.
 24 hours later, they're back at it.

If I were talking about a computer, I would say I need another terrabyte or two
of long term storage.  

Is it possible, that they (and by extension we) are capable of storing only so
much information before the excess is dumped?

Or has our research gone far enough?

Thank you for your time.

Gord Leslie
Wilson Creek
BC

Re: Do organisms learn, lose and then relearn lessons due to memory capacity?