Difficulty interpreting a poem

I have read this poem from Housman but english is not my first language and there's a part that sounds contradictory to me. Can anyone help me in understanding it?

Here dead lie we because we did not choose
To live and shame the land from which we sprung.
Life, to be sure, is nothing much to lose;
But young men think it is, and we were young.

It says "life is nothing much to lose". "Nothing much", from what I have searched, means "not much", "little", which were my guessed interpretation for it. But there's two problems: the author would be saying that life is little, therefore not a problem to lose, which doesn't match with a narrator that goes to expose the absurdity of it; the following "but" then makes no sense because it lacks something to contrapose (X is Y, but Z think 'this is the case').
The form (X is not-Y, but Z think X is Y) instead requires the inverse meaning for "nothing much", but them 'this is the case' would state "X is not-Y", which is clearly false.

I'm confused. :nonod: Is there a dual meaning for "nothing much"? No isolated case seems to work, but it would with ambiguity. If so, anyone cares to try making the raw meaning of "nothing much" to make sense for me? I would take the word of others on it, but it's not something I would spontaneously interpret (it's a bit of a ridiculous request, I know it).

Some thoughts with the hope others may chime in:

"Here dead lie we because we did not choose To live and shame the land from which we sprung." - L1 and L2 perhaps an eschewing of cowardliness by the young men revealed from death; those who fought and died rather than flee or not serve at all.

"Life, to be sure, is nothing much to lose;" L3 perhaps from the perspective of generals: young men as fodder; where honor is valued greater than life itself

"But young men think it is, and we were young" - L4 a lamentation by the dead young men.

Ta ! (short for tarradiddle),
tailor STATELY

After the intervention of Stately it has became easy to sum up what to me seems to be the tension of the poem:
Sacrificing their life for their country a sacrifice enhanced very much by the youth of the dead x leading a meaningless life "Life, to be sure, is nothing much to lose".
What sounds ambiguous to me is that "we", this collective poetic voice, that seems to speak from beyond the grave to confront both experiences.
L3 and L4-question the "narrative of dying heroically for the honour of ones country"
L3-disqualifies the worth of life, "nothing much to lose", making little of the sacrifice of it.
L4-recovers its worth partly by referring to the illusions of the young enhancing the action of those sacrificing their lives even while valuing them so much.

I suspect that Housman has invested “nothing much” with two meanings, viz. “a small and almost worthless thing” but also “easily lost”.
The young men would prefer to think that a life, especially their own, is a precious thing they would wish to retain unless, as already commented, it is better to lose it than to live in shame after an act of cowardice. The nobility of the dead lies in their not merely having obeyed orders in a futile battle but rather in their innate feelings of honour in the face of danger.

He means that life gets rotten and the old see it whereas the young are eteranlly optimistic and expectant. Life is so little that once you lose it, it cannot be found again.