Do what you need to do for yourself, just make sure you're making the best educated decision for yourself. You're coming close to that point in your life when people can't make decisions for you anymore. If you're going to join, you're going to join, whether it be at 17 or 18.
I gave up admissions to top tier UCs to try to pursue the mustang route. My peers may think they're living up the life going to school but I feel the Marines has put me light years ahead of them in terms of being financially stable and maturity. I really can't name a lot of my classmates who have: paid off a sports car, have thousands invested in a Roth IRA and Thrift Savings Plan, and will have no student loan debt without any money from the parents.
"There is an old song which asserts that "the best things in life are free". Not true! Utterly false! This was the tragic fallacy which brought on the decadence and collapse of the democracies of the twentieth century; those noble experiments failed because the people had been led to believe that they could simply vote for whatever they wanted… and get it, without toil, without sweat, without tears."