Why is it important for young people to start saving as early as possible given the principles of interest

So that you never have to take out a loan. The moment you take out a loan, is the moment you start paying back more than you even borrowed for what you were trying to purchase. In order to get ahead in life, you may need to purchase things like a vehicle, a college education, etc. It is cheaper to do this out of pocket. If you want to build credit, which is important also, you should take out a loan -- expect to pay interest fees -- but use your savings to pay it down over time. This way, you will be in "debt" but you will not be drowning in debt. Being "in debt" is not bad if you are trying to build credit, but you always want to be in a position to pay it off even if you fall under hard times (i.e. unemployed).