Should I Join the Military?

It is commendable that you desire to serve your country. There are many fine young men and women serving in the military and with some determination and commitment, you likely would be one too. I think however your reasoning for why to join is flawed. Military can train you, discipline you...but by 21 you should be training and self-disciplining yourself already and if you lack those personal self-traits, you'll just likely resist and be unhappy in the military if they force that on you.

Were you not disciplined as a younger boy at home or school?

Give school more chance to educate you and set you up on your feet for a good career. If you still want the military afterwards, it will be there and you enlist and use your education to better serve you country with your now career skills.

RJ