Words of wisdom.
My dad taught me a lesson when I was young. Never work at 100% of your ability, always work at 75%. If you have a bad day and only can work 50% that's not as far of a drop as if you were working at a 100% rate. If you work at 100% they will expect it every day give yourself a cushion for the bad days. Started a new job a couple of months ago and this rings true every day.