Well, that's the other side of the coin. Don't sign up for a twenty year career that you're going to hate.
I don't know if its still available, but there was the "Two Years Minimums" enlistment. Two years from bootcamp to transition back to the civilian world.
For some folks it made a lot of sense. They did the minimum time to get the post-service bennies. Or some basic job experience. Or some really basic training for free (plus the crappy pay check).
If you're really serious, let me repeat this- Knock off the "I, I, I,..." stuff. Think instead of serving your country. You'll still meet people who understand that and will look out for you. Try to make that feeling genuine.
If you want to join just to impress someone in the family or to have something to talk about during Thanksgiving, please reconsider. Those people you want to impress won't
be there at 2AM on a crappy duty day when the ship is due to pull out at 9 AM but the generators keep tripping off line. They won't be there when you're stuck on the surface in state 6 seas for the next 12 hours. They won't be there when the galley runs out of everything but canned ravioli, coffee, and stale ice cream cones and you're two weeks away from a dock.
If you do it, do it for YOU and do it for your country.