I think GM's in general have very good understanding of opening theory and end game. Also, they have good eye for tactical possibility and position/strategy of game. Apart from this they have played like thousands of good quality games so they can identify patterns, as in like when you start driving a car to new route you have to take notice of each and every street and turn but after a while you drive without even thinking!

That's my thought.

In life eye\hand coordination always reigns supreme. Although cognitive patterns would assist in present games. I agree with for_love_of_game.

GM dont caclculate all. Gms calculate only the lines which they feel which might give me advantage. Like in a postion there are 6 candidate moves. First they just only consider each and then calculate shallowly and then if they feel the line is good then they calculate deply

They think in triangles.

and you know it because you are one of them right, right

They mostly use intuition, and calculate to check if their intuition is correct or not.

OTOH, amateurs calculate more on average (but not as well as GMs of course).

Chess being a specialist activity, it's unclear how high-level chess skills would transfer into other activities.

All grandmasters have exceptional memories which allow them to calculate moves that the average person can't even grasp.  Harry Nelson Pillsbury could play many games simultaneously blindfolded and before his simultaneous chess exhibitions, he would entertain his audience with feats of memory that involved accurately recalling long lists of words after hearing or looking at them just once. One such list, which Pillsbury repeated forward and backward, performing the same feat the next day, was:

Antiphlogistine, periosteum, takadiastase, plasmon, ambrosia, Threlkeld, streptococcus, staphylococcus, micrococcus, plasmodium, Mississippi, Freiheit, Philadelphia, Cincinnati, athletics, no war, Etchenberg, American, Russian, philosophy, Piet Potgelter's Rost, Salamagundi, Oomisillecootsi, Bangmamvate, Schlechter's Nek, Manzinyama, theosophy, catechism, Madjesoomalops.

DO u believe in the force

Only a GM could know how a GM thinks.

GM's also follow their plan more actively. They look for candidate moves that strengthen their position. Imagine white has say Rd7 but black has the move Nf6 and then the rook has to withdraw. A GM will look for a candidate move that undermines black playing Nf6. That is they co-ordinate their pieces better and more actively.

I think learning young is a big part of it. When you learn things as a child they become second nature like speaking.  As for the part asking if they are smart in everyday life, I think some are and some aren't. Being smart isn't just being able to play chess exceptionally. Some people can calculate complex math problems in their heads, but have no idea how to conduct themselves amongst others. Fischer was a good example I think. You don't have to be very bright to know that a lot of things coming out of his mouth were awful. Not the way a champion, that have others looking up to them, should conduct themselves. Even Carlsen has had a few rants and bad interviews that I thought were inappropriate.  How can you be so smart at chess and not realize that all you have to say is the same old boring stuff when in public?

"I'm just trying to play my best, day in, day out."

"Gotta hand it to my opponent. he played an exceptional  game."  

"Hopefully with enough hard work, and dedication, it will pay off in the end"  

Just some examples. Different types of smart I think.

Yeah, experience and pattern recognition pay a huge part. There is the famous study that looked at that angle and found masters could recall positions from games much more quickly and accurately than less skilled players. But when shown random positions (that don't derive from normal games) they weren't any better at recalling the positions (or maybe it was not significantly better).

Strong players can use that experience and recognition to home in on the important parts of the position and don't look at, or calculate things a weaker player does.

When I was little, my parents sent me to a swimming club. I was and considered myself a strong swimmer and was mightily impressed by the state of the guys there. Intimidated but determined to give it my best I trained and trained and trained. I swam more than a navy seal. Then, one day I overheard a conversation between 2 coaches we had. The disappointing gist was, that you didn't get a great body and became a swimmer because you trained hard. But the purpose of the swimming club was to find the specials among the the swimmers who were already talented enough to become swimmers. So, you didn't become a great swimmer and attain a great physique by just training, the guys with streamlined figures and talented from the start (biological predispositions) were the good swimmers. They already had the good body and were good swimmers because they were build like that. Same in advertising. A beautiful model advertising cosmetics isnt there because the cos made her beautiful, its the other way round. She is advertising cosmetics because she was beautiful to begin with. The intellectual folly is, that we exchange "criteria selection" with "result". I know its disappointing, but GMs are a little different tuned than we are. But so you have a life. Hopefully rewarding. Enjoy understanding the game more and more and the journey should be amazing.

Possibly of interest:

https://www.chess.com/blog/VladimirHerceg91/using-en-passant-to-gain-a-mental-advantage