Milo nailed it Moundhill. Whether it is money from student loans or a paycheck you EARNED, don't piss it away. It is VERY easy to do at that age. I did it. I would bet the majority of guys on here did it. This is why you will hear this repeatedly. It is an easy trap. Young, money in your pocket, next thing you know 3-5yrs go by and you have nothing to show for it. It is a tough world right now. Tougher than your parents or my parents grew up in.
If you choose the work route, keep your discipline about yourself. I am not saying if you have saved up $4-5k you can't go spend a couple hundred, but with uncertainty in the global economy, social security, the housing markets, etc, the more you can save the better. If you have any questions, feel free to call me or PM me. I am no expert, but I started investing when I was about 21 or 22. Wish I did at 18. There are some investments that you cannot touch. Others it is okay to draw out of them without penalty if you are using the money for schooling or to buy a house. If you are undecided about what career choice you want to go after, it might be a wise idea to work a couple years and stash some money away until you decide.