It's reassuring precisely because it acknowledges that conundrum -- fundamental understanding often comes after a tough, rote (and uncertain) 'getting used to it.' -- so "stick with it," as it were.
It reassures me because it feels at times that the people around me who are so 'great' at mathematics are born naturals and that I may as well give up. For me is a great 'leveller' to hear that even the greatest minds struggle with these things, albeit to differing degrees.