So my dog did something pretty stupid. Any guesses as to what it was?

I was walking him, and it was kind of late, like 8:30ish or so. So I noticed he kept stopping and sitting down, and walking behind me or something like that. I thought maybe he was scared of the dark, or tired or something. Maybe he was. I don't know. But when we are halfway through the walk, he lies down in the grass next to someone's mailbox. I pull on the leash a little, hoping he'll get the hint and keep walking. When that doesn't work, I come over and pet him, because I'm like maybe he just needs reassurement or motivation or something like that. He won't move. And it's getting pretty dark. So I pick him up and walk home. God he is such a baby. And he's pretty heavy, it's not like he's a tiny dog. So now my arms are a little wonky, and my dog snootily ignores me as much as he used to.

Great day.