So ask your opponent if he allows take backs.
Importance of Tactics

I'm not a fan of takebacks. You make decisions and you live with them. And in this case, what would be the point. I learned a little something from this game and got an interesting tactical lesson out of it.
Also, chess.com doesn't have takebacks for rated games.

Thank you for sharing Loomis. I took a long look at this before I read your suggestion and came up with the same one! Of course, if it had been myself in your position I too would have probably missed it.

I'm not a fan of take backs. You make decisions and you live with them. And in this case, what would be the point. I learned a little something from this game and got an interesting tactical lesson out of it.
Also, chess.com doesn't have take backs for rated games.
I was just kidding, of course. I don't think you'd find any opponent that would actually allow it in a serious game.

This is what troubles me about practical play. In a tactic book (or on tactics trainer) how many of us would find this in less than a minute. In a real game, you get distracted by all the other considerations and bottom line, don't have someone whispering "there's a tactic here."
I don't know if making yourself calculate forcing variations on every move is the answer... as it might distract from following the thread of the game. Maybe just drilling patterns until they pop out 99% of the time is the answer? I don't know, but situations like this are certainly discouraging.

I missed this in a blitz game. As soon as the game was over I went back through the game and spotted this pretty quickly. In that case I had the advantage of knowing when my position started to deteriorate so I had better find a tactic before that happens. Still, I think I would find this in time control like G/30 or slower.

I've had tournament positions when in analysis, just playing over the game quickly to get it in my mind, I notice something instantly. Surely I have the position set up wrong, I think... no, it's correct. My opponent was rated in the 1900s and also missed this.
How is this possible? How can people miss things in tournament games that they don't miss in blitz? I'd certainly like to know Basically though, class players are awful. The better ones may have a lot of knowledge, but their application, or at the very least their consistency, stinks. It's all very pathetic and depressing to me
Here is a position from a game I just lost (I played white)
Black has just played Qf6-f4
White has had enjoyed a positional plus and at the moment has one more pawn on the board than black. But the failure to spot the winning tactic in this position had me worse off in just a couple moves.
I played 1. Qxf4 Nxf4 and seeing h6 coming played 2. Nf3. Black soon captured the pawn on f7, equalized, and then won.
What I should have played was
1. Bxg7+
and black's queen will fall after either 1. ... Kxg7 2. Ne6+ or 1. ... Nxg7 2. Qxf4
After 1. Qxf4 Nxf4 I still could have tried for 2. Bd2 trying to drive the f4 knight away from the defense of e6 and if 2. ... h6 3. Bxf4 hxg5 4. Bxg5