Influential Chess ideas/concepts/games etc.

Put a link or let us know of any chess ideas, games, concepts etc which really changed the way you think of chess or helped you improve, even if very small. The pawn square is one simple idea I learned about today. It's a simple idea but I think a good one to know! Obviously it's a small idea but anything like that. Something I should have known about a long time ago but didn't! https://www.youtube.com/watch?v=3FsVIa8VkZY

Pawn square was a good one to learn. 

One concept that I found really interesting is maintining pressure an a region of the board. Usually the center.

Before, at the slightest sign of building pressure(aka complexities), I would initiate a trade. Quite often one that had a lot of unpredictable consequences.

Now, I often find myself holding off and maintiaing pressure and looking for ways to either tip the scales or initiating an exchange when I have developed more control around it.

I have to say this is a concept that is playing a big role in the development of my game.

Yea absolutely @kleelof. I used to trade pieces for no reason or exchange pawns and relieve pressure when i could have added to it. I think there are times when you think you can get a small advantage by trading, which would relieve the pressure of a pin for instance, or an alignment or xray through pawns, but if you keep adding pressure you can gain alot more. Keep more coming guys! That was a great post I would LOVE to hear more ideas.