Which phase of the game you like?

I love every part! It´s a bit like playing three different games. On every stage you have to know something, to follow different rules and ideas. And at every stage you know, you have still to learn a lot

endgame, specifically king and pawn endings. If all you have on the board is a king and a bunch of pawns, there's no tactics or anything, you just need to remember things like opposition, outflanking, and you'll win the game.

I am the same way. I'm sure a 2000+ player like yourself knows this already (but I'll still include saying it for everyone else), but a mindset that has helped me has been evaluating if an endgame is the "best I can do" or if it is only slightly better. 

For obvious reasons, keeping the chess battle "in the middlegame" may offer you more chances to squeeze a bigger advantage instead of trading so early. An example might be a position where you are up by a minor piece (3 points of material), but your opponent is not castled and you are. In this case, being a piece up and simplifying into an endgame is a good idea (since up 3 points is a usually a big advantage in the ending). However, what if you didn't exchange Queens or other pieces here? What if you push for an attack on their exposed King instead - you can't attack without pieces and that is what you are losing if you trade for an endgame; by not entering the endgame so fast (even if advantageous), you may get a bigger advantage by keeping more pieces on the board for the time being. 

I remember hearing something like this from a live chess stream several months ago and it resonated with me. @JohnUrschel likes endgames like I do and was entering them (or forcing them more or less) with a slight advantage. It was then a stronger player suggested (I think it was IM @DanielRensch, but don't recall with 100% certainty; either way, it was good advice) that a larger advantage may be gained by not exchanging so quickly. 

Obviously, the position will dictate which is better - but having that open mindset about leaving the game in the "middlegame" phase is sometimes critical.

Haha premove Nf6 g6 Bg d6 castles c6 Nbd7   Qc7 e5

By all means: I don't mean that you should exchange (or worse, sacrifice) in a King's Indian closed position like that. Here, trading (or sacrificing) can easily put you worse. I meant game positions where you can press for an edge or enter a slightly better endgame now. 

Sounds like your position, you need to rip open lines of attack, or get ready for Petrosian-like positional play and out-finagling your opponent with shuffling and repositioning  

hmmm... "finagling"

Solid for bullet, but then what do you do after this? Especially with longer time controls? Eventually, you will have to make some "real decisions" yourself. Your solid premoving here will get a sound opening most of the time (White can't do a ton to really exploit this premoving here), but premoving the opening alone won't win the chess game

It is your civic duty to learn new phrases...

[snickers] "civic"

I accept. You're higher rated. I just got some rating points

wait what

actually every time I close the position and flag them I win for some reason. No plan > plan 

You mean the phase after winning a game? Yes that feeling is awesome. But it's not the phase of the game right?

The good emotion is starting with the last move but of course it last after the game! 

You have a very good point!  

Openings for me (beginner) look mad, Endgames are too slow or too fast (depends if you or your opponent is Q+ or so, or not ) thus Middlegame is for me the only time to try to kiII !!

In some endgames I suck even if I am a piece up. 

p

Middlegame

I am an endgame expert................... sooo endgame for me..

Opening. It is like relaxing before the actual game (if you know the theory).