Just because you're a cop that doesnt mean that you loose your heart and soul. Its natural and healthy to be curious about a persons life and how they got to where they are. It shows that you still see your job as dealing with individuals that are unique, not just a booking number and a report.
I talk to almost every person that i arrest on the way to jail about their life and what got them to the point that they're at. I try to give them counsel and hope and encourage them to do better things with themselves. Im kind of the front seat doctor phil to them. Sometimes they listen and care and sometimes they're turds to the core and dont care about improving themselves.
Its not wrong for you to care or want to help these people, thats one of the things that seperates good cops from regular cops.
Just dont let these people eat away at you or your faith in humanity or human nature. I do all that i can for people in the short few hours that im dealing with/arresting/booking them.
When i clear the jail and hit the street again i feel good that i did all that i could to help them, and i know that my job is done. If they want to help themselves from there they can but its their responsibility and position to worry not mine. From that point they can only save themselves, I cant do it for them so i dont worry about it anymore.
When i get back out there im worrying about new perps and every day is a new day.
Dont let these fuck ups haunt you.
Also, if that guy exposed some secret fear that you harbor youself of not suceeding in life just know that we all share the same fear.
When i see successful people like me in jail and they're just a broken glimmer of what they once were I worry myself that i may make one bad choice or do something that could make me snowball into a failure like them. But as long as you care enough to worry about things like that its a good sign that you'll be fine.
You ever heard the saying that crazy people dont worry about whether they're crazy cause they're too far lost to be self observant about it?
You're the same way, if you care enough about your life to worry about winding up in that guys place then just reassure yourself by knowing that you're dedicated to not making the same conscious decisions that the army guy made to put himself where he was.
He didnt draw some majical lottery ticket or fortune cookie that fucked his life. He threw it all in the trash in a matter of months. As long as you care about yourself you wont do the same thing.
ETA:
oh yeah, and dont smoke meth!