>I spent hours today doing intellectual battle with a set of formalisms that still largely confuse me. In the long run, I know this type of battle is crucial (past experience has shown that even just a few dozen hours of such grappling can lay the foundation for multiple publications). But in the short run, it leaves me feeling like I accomplished nothing concrete with my day.

I know the feeling.

Personally, I've had great success relating this to physical exercise, strength training in particular.

I don't expect to be able to lift more every day, week or even month that I go to the gym, but I understand that every day I do go and fully apply myself is building toward the next goal.