For how long does a sane person keep old business cards? In my case, it was forever!...Until yesterday.
Now that I need to do some networking, I went through more than 1500 cards collected from suppliers, colleagues, customers and friends since 1997! You could actually follw certain people's careers: Salesperson at XYZ Inc., Sales Manager at XYZ Inc., Director of Sales at PQR Inc., etc. etc...I kept about 50 or so. I know I still have a bunch dating back to 1988. Thank God, I will not have to look through them.
In the process, I also saved some notebooks which were barely used. I threw out the used pages and they are like brand new. Waste not, want not! I probably have enough notepads, notebooks, post-its and a variety of office supplies to last me at least ten years. No kidding!