Time travel
I very rarely throw anything away, much to my wife's chagrin. I have stuff that dates to 1979; that stuff has survived four girlfriends, my high school graduation, my dad's car accident, 12 moves (count 'em; I've chagned addresses 12 times since 1988), a marriage, three kids, four jobs and who knows what else. Among the stuff:
*A Big Chief writing tablet from when I was 11
*A note from a girlfriend, dated Dec. 1, 1983
*Pieces of paper that imply that I once was a member of the National Honor Society, that I graduated from high school, and that I was accepted to a college
*My clip files from 1986 through 1991
*Game programs from 1986 -- the Oklahoma-Missouri football game (Oklahoma 77, Missouri 0) and the Missouri-Southwest Missouri State basketball game in Columbia (Mizzou, 56-53, in overtime, in the teams' first meeting since 1952.)
*Various newspaper pages I designed
*A cellular phone, circa 1992. It's huge. It's unspeakably huge. It's one of those two-piece jobs, where the receiver connects to the actual unit via a cord.
*A key from a car I owned from 1986 to 1988
*Computer disks from the early 1990s
*A Myers-Briggs I took in 1998. For the record, I'm an ENTP, described as follows: "Quick, ingenious, good at many things. Stimulating company, alert and outspoken. May argue for fun on either side of a question. Resourceful in solving new and challenging problems, but may neglect routine assignments. Apt to turn to one new interest after another. Skillful in finding logical reasons for what they want." That's a little scary in its accuracy, although it would probably describe me better if it read: "Likes the sound of his own voice. Often contentious, not because he has strong beliefs but because he finds it entertaining. Excels at high-profile assignments, hates the daily routine. Short attention span. Spends much time explaining why he thinks he's right."

I could go on, but you get the point. I keep all this stuff for a reason. I only go through it once a year, maybe less. But I take great comfort in knowing that it's there. It makes me feel deeply rooted, despite the fact that I've spent much of my adult life as a vagabond. It reminds me who I am. That's knowledge that is often lost when I worry about who other people think I am, or even who I think I am.

Because ultimately, no matter what you do or what you see or what you go through in life, at some point, you always return to who you really are.