Learn English – What does ‘don’t even’ mean in the dialogue

Probably you refer to a song by Eminem. Text here:

http://de.urbandictionary.com/define.php?term=lose+yourself

In the first line we have "You better lose yourself in the music..."

Here to lose has its original sense as in "Damn, I've lost my keys." OALD has "lose yourself in something" as an idiom meaning Forget everything else and become one with the thing you are interested in.

As a maxim of life of dubious value.

http://www.oxfordlearnersdictionaries.com/definition/english/lose?q=lose

You'll find "to lose oneself in sth" at the bottom of the page (phrasal verbs).

"Straphanger" seems to have a different, and negative connotation in current US military parlance. Since this is a militarily-oriented movie, it is probably the definition that applies.

In an article unrelated to Zero Dark Thirty, I found a reference to strap hangers.

"We have a saying in the SEAL Teams about the 90-10 rule. It goes: 90% of the guys that make it through Basic Underwater Demolition/SEAL (BUD/S) training are solid Operators and go on to do great things. The other 10% are constantly bringing the community and their team down. We are always trying to cull the 10% out of the herd. In the military these guys are commonly referred to as “strap hangers”....grabbing at the straps of the good men that participated in this operation."

I found another reference in a book review titled The Poetry of Military Vernacular: Randy Brown’s “Welcome to FOB Haiku” that defines "straphanger" as deadweight.

So it means something like a hanger-on person who does not productively contribute to the mission, but who takes credit for it anyway.

I have never heard this use of this expression before, nor have I seen Zero Dark Thirty, but this seems to fit, as even the context implies a negative connotation.