Why do people find poker so 'tought'?

I mean tough in the mental and emotional sense. I have been thinking about why is poker so emotionally straining and I think I have a slightly better understanding, as I have platoed in my ability (i'm playing awesome atm) after my recent sobatical.

I think one of the problems is people overthinking in general. They forget that poker is a game of imperfect information and more-over, a game of variance. This means loosing $x doesnt necessarily mean you played the hand badly or incorrectly, and winning $x doesnt necessarily mean you played the hand correctly.

In my opinion I have been playing very well in the past 2 days (ill show you why later in post), however its very posible that I am not really playing that well, or that I am, but just as not as well as I think I am. Personally the more I play the more I learn/try to forget about how well i'm running; how big my BR size is, and just focus on the game. I dont overthink this as much as I used to. If I think i'm being bluffed I call the shove, if I think opponnent has goods i'm folding my 'monster'.

As you may have inferred I have also been thinking much more on the second level; 'what does my opponnent have'.

I'm amazed that ive been playing poker for 18 months and only just started thinking on the second level. This is a bit dissappointing but not too much so, I have been 'trying' to think on the second level for the majority of that time, but actually going with my read, trusting the range I have assigned to the villain, and then determining how my hand fairs against that range is something that has only just begun to 'flow'.

The flow of poker is another aspect I find is become more apart of my game as I mature as a player. The games (or specifically my style) tends to flow much better; its hard to explain what exactly that means; maybe i'm making fewer big mistakes, changing gears a bit more efficiently, beginning to analyse the table dynamics a bit more, categorizing opponents more quickly and efficiently, a slight increase in all of these attribures has cause by game to improve and untimately flow much better.

Todays session -

Been on a bit of a heater these last few days, everthing seems to go my way;

http://www.pokerhand.org/?1573377
- His play was pretty crazy, he posted OOP the inst raised when action was on him. I cant see an A checking this turn, plus his river over-bet screamed AIR!

http://www.pokerhand.org/?1573395
- Always nice.

http://www.pokerhand.org/?1573399
- I had a big read on this guy. A couple of hands earlier he insta called my PFR and then just called my c/bet. The only hand I was worried about was JJ (I gues he could have a Q or 6 and be trapping but I cant see him betting 60 on turn w FH after just calling flop). AA/KK both raise flop IMO. I put him on A high; his turn bet was super fast, I honestly reckon I would have folded this hand 2 months ago, I wouldn't have thought it through and would figure "he's bet huge he must be doing this with a monster".

Work is taking up a bit of my time, so i'd be happy with 500hands/day atm, hopefully I can get a bit more than that in but we'll see.

VB