The Teacher writes in Ecclesiastes:
Again I saw that under the sun the race is not to the swift, nor the battle to the strong, nor bread to the wise, nor riches to the intelligent, nor favor to those with knowledge, but time and chance happen to them all. (Ecclesiastes 9:11 ESV)
The Teacher is telling us that life is unpredictable. Sidney Greidanus says:
Accidents happen: runners can trip, the strong can be outsmarted, wise teachers can lose their jobs, intelligent entrepreneurs can go bankrupt, the skillful can fall out of favor. The point is: we are not in complete control of our destiny. Accidents can cause us to fall short of our goal. Life is unpredictable. (Preaching Christ from Ecclesiastes
It’s a good reminder to do our best, but not to lose hope when the results are less than what we’d expect. We are not in control. The results are not always a reflection of your skill. Life is unpredictable. God is in control.