Endurance means not needing each day to feel significant.

Requiring each day to feel significant is an expensive standard, because most days are not. Significance is concentrated in a handful of moments spread across years, and the ordinary days are what connect them. Needing more than that from a Tuesday sets you up to quit.

Let a normal day be a normal day. Do the work, close the book, and do not ask it to mean anything. The meaning is in the aggregate, and the aggregate needs the ordinary days.