For many who enlist, this will be the first time that you are away from home. It may also be the first time you associate with different characters from all walks of life. From alcohol, to woman, to friendships, to just plain ole no adult supervision, this will make some Marines seem as if they were injected with some magical drug. No adult supervision and a steady paycheck plus a new environment usually results in the exploration of all that life has to offer. This type of behavior is very normal and should not be seen as the Marine changing for better or worse.
Peer pressure also plays a huge role in how a Marine may change. For example, people who are shy and quiet and were picked on before the Marine Corps, they now have some confidence and self-respect. This does not mean they are changed and can now issue ass beatings like a world class fighter. It simply means that while in the Marine Corps this person will often live a lie for the most part. While hanging out with friends and having a good time, he may seem like he has learned to fit in. His shyness seems all but forgotten, but the reality is that he has not changed in that aspect. Once this person leaves the service what happens? They go back to their true self because they are no longer in the environment they were once in. There is no more pressure to fit in, so the person resorts to his old ways. The longer a person serves, the more permanent change you will see in him or her. And those who pick the USMC reserves really do not change much seeing as they are only part time Marines. You have to understand that there is a lot of peer pressure when serving in the Corps, so you very often have to be someone else just to fit in and so you don’t become an outcast.
If you are a thief, a drunk, a womanizer, a clown, a shy person, gay, soft spoken, religious, adventurous, sensitive or a respectful person before you enlisted, then chances are very very high that you will be the same person during and after your military service. Boot camp and serving in your unit does not magically transform you into a robot who is blood thirsty and ready to kill and it doesn't make you into that person you wish to be.
Reality is that a lot of teens who are thrill seekers and adventurous enlist into the Marine Corps. A lot of party-animal type people enlist and a lot of troubled teens also enlist. This is why you see a lot of "living it up” in the Marines. This is why you see many risks taken by some Marines. This is why many Marines are loud mouths and think they can take on the world. This is why many Marines feel they are alive for the first time in their lives. In the end you are the one who decides how you will act as a Marine. You can try your best to be yourself and to enjoy yourself, or you can blame the Corps for this and that therefore choosing to be reckless and foolish in your off time activities.
So do not expect to change who you truly are, but do expect a change in how you act and view things. Remember; when you enlist you begin with no or very little discipline. When you graduate you will have a vast amount of discipline. It is discipline which dictates our actions, so expect some change.
Civilians, especially anti-military folks love to exaggerate about how a Marine changes. It is important you understand that as humans, we all change, especially as teenagers. Don't let the fear of changing cause you to not enlist.
Think about this: If you don't join the Marines and go to college, don't you think you'd be doing much of the same shit Marines do on their off time?
Keep in mind some of you will have much more room for improvement while others already naturally conduct themselves like Marines.
Many who commit suicide have severe issues which they already had and when you add in the USMC lifestyle, this causes them to go over the edge. It is unfair to blame the Corps for every suicide the same way it is unfair to blame a university when a student takes his life. Reality is that people kill themselves often in life and it isn't always their current environment that dictates these horrific action.