Stanza 2 Summary

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

In a field by the river
my love and I did stand,

The second stanza gives us a slightly different setting, but it's still pretty conventional in a romantic sense. This time, the speaker is in a field by a river, chillaxing with his love. It seems like again the speaker is describing his younger self.
He's also still with his love at this point—no break-ups and tears just yet.
We also notice that there's some ambiguity here since we're not sure where exactly this field or river is. Likely, we're still in the salley gardens since the speaker hasn't indicated otherwise.
"But why all the ambiguity?" you ask, pounding your fist on your desk. (Sheesh. Calm down, Shmoopers—we'll help you sort this out.) Think about it: do songs sometimes sound ambiguous too? Usually singers and writers use this technique to keep the interpretation of the work open so as to avoid limiting its meaning. Maybe the speaker is doing the same thing here.

And on my leaning shoulder
she laid her snow-white hand.

There's that snow-white extremity again. We can't say the speaker isn't being consistent here. But why a hand this time, instead of feet?
Maybe the speaker is trying to emphasize his love's attempt to get him to understand what she's saying. When someone lays a hand on your shoulder, that person is usually trying to get your attention in a more physical way, so maybe the same thing is going on here.
We also have an instance of slant rhyme going on with "river" and "shoulder." (This is in addition to our expected end rhyme of the even lines—"stand" and "hand.")
So why did Yeats toss some slant rhyme into the mix? Well, it seems like the couple described in this poem aren't quite seeing eye to eye. He's all about it; she's telling him to cool his jets. What better way to reenact this disagreement than with slant rhyme? Even on a sonic level, the couple is not quite meshing. (Don't forget to check out "Form and Meter" for more on all this good stuff.)

She bid me take life easy,
as the grass grows on the weirs;

The young girl has some more advice for the speaker here. She tells him to take things easy in life (in the same sort of way he should take love easy). In other words, she thinks it's important to avoid putting so much pressure on life and love and to just chill out already.
She also uses the simile of grass growing on "the weirs." What's the heck's weir? We're so glad you asked. A weir is like a dam or any kind of obstruction that helps to control rivers and streams.
So, the girl is saying to be like the grass here and just let life grow naturally. Take time to watch the water rolling by.
Notice we have the same sort of simile as the first stanza that uses nature and romantic landscapes to help illustrate the girl's message.

But I was young and foolish,
and now am full of tears.

Just like last time, the speaker didn't learn his lesson. The reason? Oh right: he was young and foolish. We remember now. The "young and foolish" part is also used as a refrain in the poem since the speaker repeats the phrase in both stanzas to emphasize his point.
Notice the use of "was" here, too, reminding us that the speaker is looking back to those days when he was a young and foolish boy. (We're lead to believe that he's older and wiser now.)
So what's the consequence of the speaker not taking the girl's advice? Well, it's boo-hoosville—he ends up full of tears. We don't know exactly why the two likely split here, but it's very likely something to do with him being too pushy, judging by the kind of advice the girl was trying to impart. Tough break, pal.
In the end, we have a typical kind of ballad here that's all about love and heartbreak when we're young. It's downright impossible to really hear the advice we know we should be taking, so instead we just end up broken-hearted. The plus side?
The speaker implies that he's learned a very hard (but important) life lesson. So we should take hear that our suffering will make us wiser. Yay?