You don't have to choose between one or the other, though.
I have had a number of times I just don't remember a moment, only for a friend to show an old photo they happened to see again and a flood of good memories come back.
As always, relevant xkcd: https://xkcd.com/1314/
(though I do find myself in the "don't worry about documenting it" camp more often than not. The nagging background thought of "don't forget to take a picture" tends to bring me out of the moment, sometimes)