It's good to push to be the best you can be. BUT that's not being the Best You've Ever Been "be"... because things change.

Time, age, ability, situations and environments and in this case, course curriculum all change. So you must not remember how you "used to be" when you did your best...and instead create a new "best" for right now...

Be the best you can be for right now. And accept that maybe you could have done better "if" but that isn't now in reality.

Go for it!