The easiest person for you to fool is yourself.
Have you ever watched a sport and convinced yourself you could do it? In fact, it looks easy, and you could do better than the people you are watching. And then you walk out of the stands and try it. Only to find out that it is much more complicated than it looked.
In your head, you knew that this task should be easy, but the reality was much more difficult.
We do it with officiating, coaching, managing, and playing when it comes to sports. We do it with almost every other activity in life too. If we had that job, we could do it better. If we were building that thing, we could do it better. On and on it goes.
We are experts in things we have never tried.
That is, until we do it. Then it suddenly becomes much more complex than we imagined.
This is even true in matters of faith. If we had their job, we would handle it in a more Godly way. If we had that spouse, we would never be unhappy. If we taught that class, led that small group, had given that communion thought, preached that sermon, served those people, or organized that thing, we are sure we could do it better.
Just because you think you can do it better does not mean you can. Doing it is always more complicated than you realize.