Why Are They Giving Me Money?
The most important reason that parents usually give an allowance is not really so that you can pay for entertainment or buy special things- if that was the reason they could just give you the money on a case by case basis.

Allowances are meant to help you learn to handle your own money.  Saving, spending, budgeting- these are all things you are going to have to know once you leave your parents' custody, but they are hard things to teach.  Having a regular allowance mirrors (in a simpler way) what it will be like when you are earning a salary. 

An allowance is definitely a privilege that you should not take for granted.  If you are given one, remember to think about the point of an allowance.  Are you doing any saving?  Are you blowing it all in one day?  Are you going to your parents to ask for more when you've run out?