Earlier quoted context omitted.
What's that saying? "It's not you that owns your possessions, it's your possessions that owns you" s/possessions/data/
Photos have too much sentimental value attached to them to think of them as just another 'possession'. They will provide value to you in 10 years, 25 years, and 50 years and can't be easily replaced.
16-21 is like a personality black hole for most people. It's a time when you're super self-absorbed and you're living from moment to moment, literally changing every day. If I'm totally alone here then please ignore me, but once in a while I will run into a random picture of me when I was 17 or something and I can't help but think "who the fuck is this person".. and immediately want to bury that particular picture. Pictures with family are a different story, those I treasure immensely. But they are so few and far between, and certainly would not have been considered Facebook-worthy in my teens.