When I started playing chess several months ago, I hadn't played in years, and barely at that. I remember pouring so much mental effort into move after move, sluggishly like moving under water.
After a while I found myself seeking out a few tougher opponents to play against regularly. One of the practical results of this is a lot of lost games, regardless of the amount of effort poured into them.
Such games can be very stimulating, and scoring the occasional hard-fought victory feels just fantastic. But too much losing can make you doubt your game.
Lately, however, I've begun to play more games against new or rusty players, both OTB and online. This proved educational in its own way, because I could now see that my play and skills had changed dramatically over the last several months.
I could play and win, or throttle it back and drop a few pieces to even up the game, pause to teach something on the board only to replace the pieces in their previous spots, etc.
It's all about perspective. I've watched my rating drop as my playing ability improves almost too gradually to notice.