children guessed(but only a few and down they forgot as up they grew autumn winter spring summer) that noone loved him more by more
It looks as if our earlier suspicion about the seeds symbolizing children might be right, because children are the first thing we hear about in the third stanza. The poem tells us that these children "guessed." But what are they guessing about? Well, you have to jump ahead of the phrase that Cummings puts in brackets and look at line 12, which says "that noone loved him more by more." So it sounds like the children of the pretty how town suspect that noone really loves the "anyone" who this poem is about.
Or at least noone loves him "more by more." This is another weird phrase, but it might mean that noone loves "anyone" more and more as time goes by.
Still another possibility is that anyone actually has found somebody, somebody named "noone." Maybe this character "noone" really does love him "more by more." We'll have to keep reading to find out.
In the meantime, let's jump back to what Cummings—or more accurately Cummings' speaker—says about the children in parenthesis. Halfway through line 9, we read that "only a few" of the children guessed that no one loved "anyone." Further, these children seem to forget about this question completely as they grow up.
Cummings makes this idea even more complicated when he writes, "down they forgot." So now we're back to this weird thing where we feel like our world is moving up and down at the same time.
How do we make sense of the idea that forgetting is a sort of "downward" movement? If you think about it, forgetting something is a way of losing something, the same way you might lose inches off your height. So Cummings might be saying here that as the children of the pretty how town grow up in physical size, they actually get smaller in some way because they start forgetting some of the stuff they knew as children.
So what then do the children lose as they get older? Judging by what Cummings has written, the children forget to wonder about whether "anyone" has someone to love him. So, in this sense, the children become more like their parents, who, according to line 6, don't care about "anyone" at all. At this point, Cummings suggests that children might be more sympathetic to a stranger like "anyone" when they're young, but they stop caring about him as they get older. Sad, right?