I've recently returned from Barcelona.  I had a great time doing touristy things–visiting the Sagrada Familia, going on the telerifico de Montjuic cable car, roaming around Parc Güell, strolling down La Ramblas etc.  There was one touristy thing, however, that I didn't do.  I didn't insist on someone taking a photo of me every time I set foot in a new place.
Some people not only have their picture taken, they preen and pose as if they're on a glamour shoot.  All they appear to be interested in is having something to show friends when they get back that they were there–except, of course, they weren't.  They were already back home showing off their photos in their mind's eye.
There is nothing wrong with having a few snaps of yourself, but how can you appreciate where you are if you don't give yourself a chance to linger and look around, to think and to imagine?  If you do, you'll find the things that are really worth taking photos of and keeping in your memory forever.