[redmarion]

The down and dirty answer.
Calling is a small error and cost you one big bet if you are wrong.

Folding the best hand is a big error & could cost you 9.5BB.
This could be the difference in having a winning or loosing session.

If you fold the best hand, and you aren't going to win money this session, it will take you 19BB to ovecome the error. You have to cover the lost and the potential wins you could have made with those extra chips.