Why do people think centuries end one year before they do?

[VGPolyglot]

Humans work in a decimal system. However, must of us view it as going from 0 to 9, instead of 1 to 0, so must people think 0 1 2 3 4 5 6 7 8 9 and then the new one at 0, instead of 1 2 3 4 5 6 7 8 9 and then the new one at 1. That's my guess.