We know most of Blake's early poems (those in Songs of Innocence and Experience) are supposed to resemble children's poems, but, darn, sometimes they can be just a little bit tricky. "London" is a good example of this. While for the most part the poem is pretty straightforward, there are some weird little metaphors (what, exactly, are "mind-forg'd manacles" anyway?), and some parts that are just downright confusing. We'll go ahead and say that that stanza about the soldier sighing etc. is pretty tricky. Heck, just check out what we have to say about it in either the "Detailed Summary" or "Symbols, Imagery, Wordplay" to get a sense for how un-childlike some of Blake's supposedly childlike stuff can be.