HS Poker, players often look at their hole cards again during hand?

[Granite]

Hi,

Something I have been pondering after watching some episodes of High Stakes Poker. The players often look at their hole cards a couple of times during the hand.

I have only played low stakes live and people checking their cards during the hand is normal. I just check my cards once, and that's it, its stuck in my mind exactly what I have. No need to look again. I only check my hole cards for deception value.

So at these stakes I would assume that the proffesional players would be able to remember two cards and their suits, it's not a big ask. So are they looking to give off tells? Or is it because of the money involved they feel the need to recheck to see if they remember right?

Cheers,
Granite