It is a question of opportunity cost. If you are studying openings at the expense of doing tactical puzzles and sharpening your tactics, it is not the most efficient use of your time at the 1200 level.

If you have a 1200 level tactics skill and 1500 level openings skill, you are going to be about a 1200 rated player. If you have a 1500 level skill in tactics, you are going to be about a 1500 rated player regardless of whether you've studied openings. Remember: Being able to calculate tactics better helps with openings! Just because your opponent has memorized something and you haven't doesn't mean you can't just calculate on the fly and avoid falling into obvious traps.

Yeah I'm not so sure though. I'm 1900 rated tactics on lichess but a middling 1300 on normal games. Perhaps it might be due to playing blitz where I don't have lots of time to think.

I guess it also depends on what openings you play as black. For Caro-Kann or French defense you probably only need to know some good spots for the pieces and some typical plans, but if your reply for 1.e4 is e5 (which seems to be the most popular response among beginners), then you'd better be prepared for King's and Danish gambit, Italian or Two knights defense and so on, because in all of these openings it's easy to get mated in 20 moves while making only seemingly logical moves or get into a situation when you have to find the only defensive moves, while your opponent just throws pieces at you and keep making new threats.

I'm at 2250 on Lichess, and I consider openings a waste of time. Ok, I confess I wasted a lot of time on them in the past, and my rating was rather constant for years and years, until I started tactics via the woodpecker method. It's hard work, but definitely worth it. (quite a few of the easier exercises are opening tactics)

https://www.amazon.com/Woodpecker-Method-Axel-Smith-Tikkanen...

From the (linked above) Amazon description:

> The quick explanation of the Woodpecker Method is that you need to solve a large number of puzzles in a row; then solve the same puzzles again and again, only faster. It’s not a lazy shortcut to success – hard work is required. But the reward can be re-programming your unconscious mind. Benefits include sharper tactical vision, fewer blunders, better play when in time trouble and improved intuition.

This seems pretty similar to the Chess.com "puzzle rush" game, although I'll admit that I haven't actually tried that yet.

What age did you get serious with chess? 2200 in lichess is high.

I started too late: 17

Funny how everyone that says openings are waste of time have already wasted their time on them and built an opening repertoire :)

What do you do know, play specific openings or move by instinct until reaching the middlegame? Willing to bet it's the former.

My current strategy is this (mind I do have knowlegde, it just needs expanding) Whenever I play a game, I check afterwards from the point where the preparation (and my knowledge) ended what I should have played, and if it's in line with theory.

  - If the move I played is in line with theory, I don't bother trying to remember it because I can find it. 
  - If there are more than 1 plausible move in theory and my move is one of them, don't bother because I can find it.
  - If theory happens to be something I can't find on my own, then I investigate the idea behind it and automagically I remember (at least for some time)

But you only need to get a bit better to see through the common traps even the first time. The very first time I saw a scholars mate attempted against me I thought the moves were weird and made the obvious tactical response, only end up down a pawn. I was annoyed at being down a pawn afterwards and looked it up the opening, and only then did I discover the so called trap that I unknowingly didn't fall into because there are several good defenses that someone who knows even a little tactics will discover.

Now at the 2500 level you get into sequences where you need to see a trap 15 non-forced moves in advance to not fall into it with seemingly natural moves. These can only be found in advance.

Hold on... you're 2500?

I doubt it. Actual 2500 rated players aren't looking 15 positional moves ahead during a game.

I didn't say 2500 raters players look 15 moves in advance in games (though in some simple endgames they can see farther than that). I said that they can see 15 moves in advance when they spend weeks (or even years) before the game preparing their openings. It isn't unheard of for players at the >2000 level to pull out a planned novility 15-20 moves into a game - a position never before reached in chess that they prepared for one specific opponent in a tournament.

I don't have a rating, but somewhere in the 1000-1300 range is a reasonable guess. I have beat a USCF 1500, but that was 1 game out of hundreds.

I don't need a 2500 rating to know something about how they play.

It seems more likely that the players you're facing have one safe opening that they almost always play, so they know from experience where it can accept modification at this level.