Stanza 2 Summary

Get out the microscope, because we’re going through this poem line-by-line.

When I was one-and-twenty
I heard him say again,

Wow. This advisor just doesn't stop.
Our speaker also seems to be falling into a nursery-rhyme like litany: "when I was one-and-twenty" sounds like part of the answer to one of those games where your teacher asks you what you did when you were five – or six – or, well, twenty-one. Either he's beginning to laugh at himself for the silliness of his old beliefs or he really does have the mentality of a nursery-schooler.

"The heart out of the bosom
Was never given in vain;
'Tis paid with sighs a plenty
And sold for endless rue."

OK, now we're beginning to understand why the wise man doesn't think falling in love is a good idea: it sounds like he's been seriously burned in the past.
Notice how our speaker continues to refer to his heart as a thing – something that can be ripped out of his chest and traded for other things. He's sure not listening to The Beatles – "The Love you take is equal to the love you make" isn't really a lyric that he'd be a fan of. Cynical? Perhaps.

And I am two-and-twenty,
And oh, 'tis true, 'tis true.

Here it is, folks. The Moral of this little story. (That's "Moral" with a capital "m," in case you were wondering). After all, any poem that starts out with wise sayings that get ignored is probably going to finish with some "wise" musings of its own.
Wise men, as it turns out, are always right. Got it?
OR: Love sucks.
See? We told you that this would be a fun little poem.
At least we're laughing with our speaker. He seems to get the joke better than we do…after all, it's a joke made entirely at his own expense.