Wikipedia: It is distinct from the century known as the 1900s which began on January 1, 1900 and ended on December 31, 1999.
How about simple logic?
A) There is no year 0, therefore the first set of 100 years must be years 1-100, the 2nd 101-200, etc.
B) Everyone who was conscious for New Year's 2000 remembers this ad nauseum topic.
C) No one cared.
Anyway, if you liked this one, try my 19th century events quiz: