the world consists of 10 types of people

Those who understand binary and those who don't. And other pre-windows jokes. One I liked was the BASIC approach to explaining the difference between two abitary divisions of humanity.

Type 1 runs like this:

1 BEGIN PROGRAM

2 IDENTIFY PROBLEM

3 IDENTIFY CAUSE OF PROBLEM

4 RESOLVE PROBLEM

5 GOTO 1

Type 2 runs like this:

1 BEGIN PROGRAM

2 IDENTIFY PROBLEM

3 ASSIGN BLAME

4 BITCH ABOUT PROBLEM

5 GOTO 1

You can asign your own values to types 1 and 2 remembering when you do how much your choice says about your own prejudices.