Why Is My Bag So Heavy?

Some days the obsessive compulsive side of me wins.  Some of the more ridiculous things I found while meticulously cataloguing the contents of my bag:

1 voice recorder (do I ever use that?)
1 expired diplomatic passport (can't quite bring myself to chuck it yet)
2 old college IDs (hang onto that Spring 2000 Pomona ID, never know when it will come in handy)
2 16 meg SD cards (can fit 3 pics each)
3 tire adapting valves for my bike
4 tubes of used lip balm
5 pairs of earphones
100 sheets of graph paper (have to be exact!)

And to contain it all:

1 wallet
1 airplane overnight kit bag
1 computer sleeve
1 mini folio
2 pencil cases
3 makeup bags
4 folders
228 Gigs of memory spread across ~12 devices

I don't know if I could even make the 100 Things Challenge just with what I have on my person and in my bag.