It took me a long time to realize this, but I can't control everything. I can control how I react, the process I follow, my attitude, my character, my effort, and several other things... and that's it.
Epictetus, who was born in 50 A.D., speaks about this in Discourses (which was all written down by a student of his... amazing). But what we need to consider is what's in your control and what isn't, and, often more importantly, how we respond to it.