I've got a theory that if you give 100% all of the time, somehow things will work out in the end.
Larry Bird, former NBA basketball player
We are constantly telling our kids...
"Always do your best. As long as you give your best, all of the time, we will never be disappointed in you."
It isn't someone else's 100%, it is just yours. You know your limits, expectations, drive, focus. You know whether or not you have given it your all. You can't be fully satisfied with yourself, unless you truly give your 100%.
Give it your all in everything you do!