I'm not sure if this is the right place for this, but my friends and I were camping over the weekend without google in our pockets, and we ended up getting into a debate until 3 a.m. over this question.

Some of the points that were brought up, consolidated from both sides of the argument:

• Most mammoths died around 10,000 years ago, but populations existed as early as 4,000 years ago. The formation of human civilizations during this time span could be a game changer.
• People have the ability to ride elephants, so theoretically they should be able to ride a mammoth.
• At the time mammoths existed, people were preoccupied with survival rather than getting on mammoths for fun.
• Mammoths may or may not have been too big to get on at the time, given available resources.

The debate went on for several hours, and we really did want to arrive at an answer. Any help getting to the bottom of this would be greatly appreciated.