You sound a lot like me. I was lazy, unmotivated and undisciplined. I was also really smart. I got a 99 on my ASVAB, the highest score you can get. I qualified for any job in the military, and I ended up in Electronic Warfare.
The problem with the military for hyper-smart people is, if you’re really smart, you look for smart ways to do things. But the military is not interested in smart ways of doing things. They’re interested in people that can do it the way they want to do it.
There is no career in the military that makes up for this. You’ll never be happy because you’ll never feel like you’re being used to your fullest potential. The only exception I can see is being a fighter pilot. You might try combat fields, but unless you really want to see combat I’d suggest staying away.
Believe it or not, I believe a corporate job is the best place for a smart, but lazy person. There’s enough other people around so that you don’t have to do a lot of work, and there’s enough time and resources to devote towards being smart and having insights and the like.
Desk life is underrated. Things can get really challenging, requiring your full attention. You can always go work out, these days nobody is really chained to a desk. If you’re good at what you do, pick a decent field, you can earn perks. There’s no guarantee that you won’t end up flying a desk in the military either. Even if you have an active, interesting career, active, interesting situations are rare.
I’d hate to see you re-learn the lessons I learned by joining the military.
Grades are all but meaningless these days. Just put in the hours you need to get your degree and spend the rest of your time on side projects or even a side business.