Laid back
An individual personality whom doesn't feel like he or she needs to take charge, can let things slide, go with the flow in a sense.
Example:
Bob: Dude, why are you not bothered by what that broad did to you?
Dave: I'm laid back, man. No point in taking it personal.
Bob: Dude, why are you not bothered by what that broad did to you?
Dave: I'm laid back, man. No point in taking it personal.