I can fire one shot at a deer at one time during the yearbut I can shoot da heck out of a piece of paper, do it year around, and I enjoy it. It's just another way of challenging yourself and a nice hobby (which I've not done enough of for the last two years).
So far as good days and bad - yep, and they sometimes fall on the SAME day.

Check the first three shots in the group below (same rifle as used for the targets shown before). I should have stopped at 3, before my day turned sour - too much pressure.

Shot 5 was an "I no longer care" shot. I save that picture to remind myself of what WOULD have been my personal best 3-shot group at 100 yards ... had I stopped.