Very few pitchers go undefeated during a baseball season; many pitchers go through slumps where they don’t have their best pitch working, where they can’t throw strikes, or can’t get hitters out. The very best pitchers pitch through these woes and do the best they can given their physical, mental, and emotional abilities at that time.
Similarly, in the workplace, one can’t be on 100% of the time; there will come days where you’ll need to work a longer day or a shorter day to meet your limitations head on. You may have to make decisions after a sleepless night, during a physical ailment, or after having an emotional roller coaster of a day. The important things to remember are to shut down when you need to, work through the difficult times, and rely on your support network to give you the kind of attention you need to work through the tough times.