Endurance is patience concentrated.

Getting through something hard is not a separate power from waiting well; it is the same thing pressed into a smaller space. Patience spread across a quiet month looks like calm. The same patience compressed into one bad afternoon looks like strength. You already have the material it asks for.

When something is grinding on you, stop asking how much more you can take and ask how much of the next hour you can wait through. Endurance rarely requires a decision about the whole stretch. It requires staying with this part, and then the part after.