When I was one-and-twenty
I heard a wise man say,
"Give crowns and pounds and guineas
But not your heart away;
Give pearls away and rubies
But keep your fancy free."
But I was one-and-twenty,
No use to talk to me.

When I was one-and-twenty
I heard him say again,
"The heart out of the bosom
Was never given in vain;
'Tis paid with sighs a plenty
And sold for endless rue."
And I am two-and-twenty,
And oh, 'tis true, 'tis true.

Alfred Edward Housman

http://www.poemhunter.com/poem/when-i-was-one-and-twenty/