Probably, you are one of the rear visitors of http://3.141592653589793238462643383279502884197169399375105820974944592.com/ ;)

Actually, no - but thank you. It was an old school competition to remember the most. That's the residual memory of it.

Remembering millions of digits of pi is trivial. Given time, I can cite a billion of them. Just don't ask me in which order they appear. Now for the useful constants I remember:
1. 0 - first interesting number.
2. 1 - last interesting number.
3. 2 - number of eyes typical humans and penguins have.
4. 3 - number of vertices of a triangle.
5. 4 - number of players needed for a game of bridge.
6. 5 - most symmetric multi-dotted face on a die.
7. 6 - number of days in a week, not counting Wednesday.
8. 6.5 - halfway 13.
9. 7 - number of cardinal sins.
10. 8 - only digit to divide the plane into three mutual exclusive subsets.
11. 9 - number of known planets in the solar system.
12. 10 - both interesting numbers!
13. 11 - road number between home and work.
14. 12 - number of steps of our staircases.
15. 13 - twice 6.5.
16. 14 - silver.

Abigail