Is psychology in chess needed to become a stronger player ?

Psychology in chess is not needed to become a stronger chess player or to get better results though it can sometimes be useful.
But ... perhaps you have already used psychology in chess without knowing it.
Maybe you were hanging at a bar at your chessclub and you heard a fellow chess player say that they really dislike the Marshall attack of the Ruy Lopez. And then during some weeks you decided to study that particular variation at home, and when you got to play that very chess player at your club you did opt to play the Marshall, for the very first time in your life, and you won the game !

Or perhaps it is in little practical things which are more about pragmatic superstition then about psychology, like wearing your favorite, but worn out, t-shirt at an important chess game in OTB chess because you know that you always feel good in your favorite t-shirt.

Or you offered a draw in an OTB game because you know that this player really dislikes draw, and your draw offer was just to try to get them in a different mood. And they did, they became furious, overstretched, they wanted to win at all costs but you kept your cool, and slowly converted your winning advantage.

Please share your thoughts and experiences in the comments. Thank you.

tldr; is Too Long Didn't Read, an expression that becomes more popular in some parts of the world where life may seem to become more hectic and people have less time, or are less willing, to read longer texts.