As some of you have already said all people do at some level or other. It may not be decisions that we concioulsy make but simple things like the clothes we wear, how we interact with others, what food we eat, what we get upto in our spare time, basically our own self image is what we think others think of us or how others see us therefore on some level we all care.
Diaz said he doesnt give a fuck because he is a " tHuGgISh RugGiSh StOnE cOlD oUtLaW rIdAh!@!@!@! " yet he fails to realise he does because he wants us to think that he is an outlaw.
EDIT: I think if u were living as a hermit u would truly not care what others think of u, personally I do care what others think of myself. Professionally, appeasing my managers is the only way I'm going to move further up the chain, but personally, I take care of the people I know and as long as I do that I know they got my back.