I had always considered myself a pretty good amateur chess player, but at the first tournament in my life I faced a harsh reality. In the deciding game my opponent (a candidate master) put me in a difficult position - I couldn't see any good continuations and was already mentally giving up.
There were 3 minutes left until the end of the game, and I furtively took out my phone with a chess calculator. I quickly entered the position - the program showed an unobvious knight move that I hadn't even considered! I made this move, and a few minutes later my opponent ... made a mistake! It ended in a draw, which was a small victory for me.
Now I only use a calculator to analyze after games - an honest game is still more pleasant. But that incident taught me that sometimes the right move is sometimes where you don't expect to find it at all.
