Re: Firefly first-time/rewatch (NO SPOILERS, please)
Mal's chronological age is irrelevant. He spent a big part of his life fighting a war, and a big part if that commanding others. If he's not old in years, he is in life experience.
The fact that he refers to others as "son" or "boy" only emphasizes his war-weary attitude. I thought it was obvious.
Yea, Simon was 27 going on 18, and Mal was 31, going on 45
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?