I just played that game in a German Chessleague today. Our Team lost 2:6 and I lost too. After 12 years my first OTB game, first one as an adult.

And right away I had a super strong opponent from my standards. Fide Elo 2148, German DWZ 1929 - against me the beginner.

Here is the game:

It would be great to hear some thoughts, positionally I didn't stand to bad quite a while considering his strength.

I was white btw.

Good effort. I only skimmed through it but I can tell you this.  I don't think 4. Bg5 is a huge error. I am more used to seeing ideas like 4. Bf4 followed by h3 at some point (generic london system set up).  On your 6th move it would have been hard for me to resist playing nf3.  You should think of most openings as an "arms race" where every move is precious.  Can't afford to spend tempi moving the same piece around unless you get something really good in return. I agree with your assessment of your 14th move.  Opposite side castling middlegame and I can't see a clear reason why black should be better so "Tora Tora Tora!". Good effort!

13. g4!

Chess is the one place where your real-world personality does not have to reflect in your board personality. Just because you are not a real world super hero does not mean you can't play like one at the board.

after 13.g4 I see a lot of complicated play where White is not worse.
 

just a sample variation, but I want to illustrate the importance of running your agenda instead of waiting to die.

Add me as a friend! :)

Beautiful! That would have been crazy and awesome if I would have thought of that, I still had more than one hour on the clock at this point. After the game he said he would have taken the pawn fxg4 so...

So more aggressive next time ;)

Thank you very much for the insight.

I lost a Tempo in the Opening already, so that was not very good. But it was a strong opponent so I am not really sad about the loss.

I was in love with the open h file for my rooks, but it was very hard to stick to that plan.