I miss this interesting post from Nigritude Ultramarine .

Almost every one of my friends has, at one point or another, made at least one Excel spreadsheet to document some arcane aspect of their lives. The number of consecutive sunny days, the types and prices of the cups of coffee they drink, or just straightforward charts about their boss's mood.(...)Have you ever made a spreadsheet for your personal life? Talked to your kids using PowerPoint? Share your geekiness, and maybe it'll justify the creation of an exciting new community of dorks.

I did that at the end of the dot-com bubble, carefully noting the CAC40 numbers... I also have one for my CD list (not updated) and a txt file for my book/movie list.