A quote by Cavett Robert - "Character is the ability to carry out a good resolution long after the excitement of the moment has passed."
Substitute "determination" or "commitment" in place of "character," and I think it's still on point. At the end of the day, when motivation fades, all we're left with is "character." It's about the little decisions you make when no one is watching.
"Character" morphs to "lifestyle" long after the hoopla goes away. And the hoopla ALWAYS goes away. So deal with it!
From Abraham Lincoln - "Character is like a tree, and reputation its shadow. The shadow is what we think it is, and the tree is the real thing."