Most men who have heard of the Legion and its soldiers, knowing that it is a haven for misfits and the life is hard. Most would also wonder if they have the "right stuff" to make it through and become a legionnaire. This story is one of someone who made it through, loyalty among men with little else in life, and the brutality that can be normalised through repetition.
The author is at least introspective and acknowledges his feeling superior to others and truly believing everyone else is below a legionnaire. As such his antics in other countries and in public back home are really those of an immature boy who has no real consequences to his actions, he dismisses his lucky escapes to being invincible. Even as a mature man writing his biography he feels the need to glorify his exploits at that time which still seems immature.
Armies take boys, strip them of their identity and shape them back as a team that would not let their team mates down. Every army is the same and the legionnaire is no different, so that part of the story is unremarkable.
The ability to work well with little to no sleep is also a myth, I am sure at the time it seemed good but how could a soldier operate well when hallucinating from dehydration or fatigue. He can't, but I guess the author felt he did.
Anyway, an interesting read but full of false bravado that does not impress like the author thought it would.