Like anaconda said, the first three months are basically tap city (that is, if you are rolling with senior whites and above), and it is indeed frustrating.
Instead of getting angry at myself, I thought of it as a learning experience. I was addicted after the first week. After every class (even to this day) I think to myself, and go over what I did good, and what I could use improving. I'm always working on my weaknesses and trying to come up with better defenses and moves to use in the next class.
I starting getting my first taps at about 3 - 3 1/2 months in. Mostly armbars from the guard on other newbies. After 6 months, I was getting more armbars, now mixed in with triangles and omoplatas (again, on other whites). I didn't start 'getting it' and becoming more well rounded until about a year of training.
Jiu jitsu is a journey. There is never enough to learn. You should be learning something new every class. If not a new technique, then a new transition, sweep, escape, combination, etc.
It's tempting to always go to your A game, but the best way to learn and improve (IMO), is to put yourself in bad positions, roll with and observe higher belts, and work on what you are worst at.
Basically, be the opposite of bma_matt (sorry, couldn't resist).
