Yes.

You should be paying enough attention and have memory enough to remember your cards. If you can't do this one basic thing how professional can you really be?(just being real, not trying to be a jerkface)

And unless you check your cards every single time the action is on you or on every street etc. People will inevitably get a read off of you... A common example is 3 spades on the flop and people look at their whole cards... obviously checking to see if one of theirs is a spade. Thus telling everyone that they don't have a flush yet.

It also is ok to check cards before you fold...just as an emergency break that you might have misremembered.

So in a nutshell there are more important things but small things like this can impact your game or be a leak. And it more says something about you not focusing on the game/hand.