Oh, the infinite cruelty of mathematics! Between 0 and 1 lies an uncountably infinite set of real numbers. That's right - no matter how long you sit there listing decimals, you'll never finish. Not in a lifetime. Not in a billion lifetimes.
This is basically the mathematical equivalent of asking someone to empty the ocean with a teaspoon. Even the most dedicated mathematician would just stare at you with the same horrified expression Chandler has here.
Next time someone tells you math is just "basic numbers," show them this and watch their soul leave their body as they contemplate the concept of infinity.