You can read this poem here.
This is one of those poems I read and simply think, ‘Yes’. The simplicity of the rhyme-scheme and the regularity of the metre feel part of the irrefutability of what the poem has to say. It seems very Housman that he’s feeling such a drive to make the most of his time at the not-very-old-really age of twenty! I started mentally re-writing stanza two to say ‘Now of my threescore years and ten/Fifty will not come again’ and then realised it was all going to go wrong at the end of life three, so abandoned that… But however premature his worry may seem, about running out of time, his point stands: that spring is a time when we may connect with the joy of renewal, the beauty of the world, and the anguish of our own fleetingness. I think Housman has it right, though. The only thing to do, in the end, is make the most of what you get. About the woodlands let us go…