What causes sudden behavior changes?

What causes sudden behavior changes like this?

• its since like a month the way i behave is changed a lot. i used to be like wicked calm and easy going but now its like i'm not me any more, i had my job (part time coz i go to school) since i was 17 so for 4yrs i was scared to quit because it was had o find another job altho i didnt need one since my parents still support me, well i quit in a heart beat coz of a very small issue, i used to love my stuff like take good care of my things now its like w/e i thing if it breaks i can buy another and nothing lasts for ever, i drive like a crazy man now, and i used to be the peace keeper if a fight breaks up i would stop it now i start stuff, and off no where couple days ago i just signup for the marines even tho i did good in school, and i'm happy about it too i'm so pumped for boot camp. the only thing in my head right now is that pain is temporary you only get one life and have to live it to the fullest. i used to be really scared to talk to girls never had a girl friend but all sudden i don't any more and i never realized how easy it is to get a girl to bed. really what is going on with me, I know i'm like going crazy but i only think that stuff when i'm home like going to bed or just bored and most the time i'm out and well i'm a crazy basted there, in a way i like it but the same time its a little dangerous, my friends make fun of me saying that i'm possed, but what could have triggered this

• Answer:

  Possible that you have depression or you are bi-polar. Go see the doc you need to get checked out.