1. Random New Yorkers cheering for total strangers (enjoy it now—doesn't happen often).
2. A runner waving their arms to get the crowd more pumped up. Wait, isn't that what we're supposed to be doing for them?
3. Runners wearing Greek-style leather sandals.
4. A joggler (yes, that means someone who juggles the whole time).
5. Someone who's really, really into their playlist.
6. Athletes going so fast you'll be convinced you're not the same species. (You’re not.)
7. Runners wearing shirts that tell you who they're running for, which will make you cry.
8. Some guy who’s made a really amazing costume, but realized two miles in that there is no way in hell he’s going to make it without at least taking off the helmet/chainmail/wings/hospital bed/other person strapped to his shoulders.
9. A lot of those really gross toe-separating running shoes.
10. Technically invisible to the human eye, but loads of athlete's-foot microorganisms multiplying in said running shoes.