I'm sure i'm not the only person who feels this!! Why is it, that one day you can look at a position and think 'I'm screwed, this guy really knows what he's doing, how am i going to get out of this???', only to come back to exactly the same position a day or two later and go 'OH!! LOOK, if i do this, then this, then this, i win his QUEEN!!! What is that??? Inspiration? Chess blindness?? I dunno, i guess that's why i end up using all my timebank in EVERY game... 😉

The reason why you could see the move now and not then is for a few simple reasons.
1. First, you are not the same player the last time you looked at the board, with each study or analysyst you get better
2. You are physically different. The amount of sleep you had before you looked at the bored, the amount of food (energy-nutrition) you had in your bleed stream is different.
3. Your mentally different. Likely, but not guarenteed, something is different. You might have been stressed out about something and now wiht a clear mind you are ready to win.

These are the 3 key components (in mind) that affect your ability to percieve a move. To ensure you see the important moves its important that you (and yes each answer will combat each problem area)
1. Use your time, as each second of study passes you are getting stronger, so take your time and the move will show its self.
2. Get the sleep and food you need before playing serious (tourny) chess or try to avoid making RHP moves when ur tired or hungry or need to go to the bathroom.
3. Don't let anything like your job or family problems get in your mind. Chess is for you, not for them, this is a time for your stregths.

these 3 help

I have found that to be the case many times as well. Sometimes you just feel like you are losing and become needlessly anxious, it is a weird feeling. Especially when you return and you see how wrong you are as you said.

I have found that games I am uncertain about are better to sleep on, if you can, and that your mind will keep at the problem. I often find myself having a move in a game "click" in my head when I am not even around the game.

But I agree, that is a weird feeling!

I have the same problem. One thing I have been working on is fighting the urge to resign hopeless looking games. I have actually won two games now that I almost resigned. And even if you can't win sometimes you can draw.

It has really pissed off a few people, but my new system is to almost never resign, make them mate me even if they theorhetically should have no problem. Not only do I keep my spirits up and see better moves, they get frustrated and screw up.

Could also be a case of incubation. You set your mind a problem and it cranked away at it while you attended to other pertinent facets of your life. Then if a solution was found (alas cogn. psych has not found all answers...) it shows up as either the Aha! moment or when you look at the problem again and suddenly it is asif you suddenly awoke. The factors mentioned in the other posts also play a role in this. Anyway, hope that helps.
You can also purposefully do this. Look at or analyse the problem the best you can, then mentally make a note of it and then believe that an answer will be found. Then do something to completely take your mind off of it and then sleep on it for a day or two...The mind can do amazing things if properly directed.

you get a pretty good indication of how you react to sleep/hunger etc. by doing CTS. with actual games you get a vague idea, but you don't really see the concrete effect. on CTS, you'll see it all in clear numbers, and even in a graph. -currently I score around 1520 feeling normal, 1490 when I'm tired, and 1470 when I'm exhausted. 1480 if I just ate, but on the other hand, hunger doesn't affect me at all. the difference doesn't seem like much, but there's also the success rate which plummets for the same reason. from 1 failed in every 10-15 problems to 1 in every 4 at worst.

translated to rhp, my '1470 CTS feeling' means I'll blunder away maybe 3 out of 10 of my games. at '1520-feel' I don't blunder any.

as a result, I now have a lot better feel for when I should refrain from moving. I no longer think I can pull off tricky moves just by focusing more when I'm tired. now I know I won't find the right moves then, so I skip the games for later and let the timebank burn.

well I try skipping anyway. failing that, there are always games lost.

I've noticedthat sometimes in a multiple day tournament the first day I may not be playing my best. I go to sleep at night and something seems to click. Maybe it's because I'm dreaming moves or something, but I play much better. (And it's not because the 1st day I was tired and the second day I was rested. Both days I got the same amount of sleep)

This has happened multiple times.