A tiny riddle rhyme about going to fetch something, losing it, and bringing home the loss instead. Its puzzle logic makes it a good one for a slightly older child to turn over.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
I went to the wood and got it;
I sat me down to look for it
And brought it home because I couldn't find it.
About this rhyme
Text checked: 'I went to the wood and got it; I sat me down to look for it And brought it home because I couldn't find it.' The riddle's answer is a thorn (per the site's own title). The standard gloss of this riddle (found across riddle collections) is that the thorn is already embedded in the person's skin the whole time, which is why looking for it fails. No source specifies 'foot', though.
A proper riddle, and a sly one. The teller goes to the wood, sits down to hunt for the thing, then carries it home unfound, because the thorn was already stuck in their skin, too close for them to spot. Read it slowly and let the logic land before you explain.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition