That doesn't strike me as weird as the odd occasions I've seen men's underwear in the street. How does THAT happen?

I throw mine in my bag, and I think they sometimes fall out when I'm digging for other stuff.

Some guesses:
Overfull pockets/bags, so that when they are digging for other things, they don't notice the holder falling out onto the ground
Poorly tied hairties/thin hair, which causes the hair tie to gradually slip off. This is a problem I have.
People keep them on their wrists sometimes...maybe they absentmindedly pull them off as well?

I wear mine on my wrist. It makes quite the chic fashion statement, you know. Minimalist industrial design, basic black, flattering.

The ones in the street are probably mainly those that have slipped from ponytails. Mine fall out sometimes when I run.

But wouldn't having your hair suddenly in your face make you turn around and pick up the rubber band?

When I had a pony tail, I just kept a few in the front pocket of my daypack. The ones you see on the street might be mine because I would buy a whole pack of them and then a year later, buy another pack of them.

But wouldn't having your hair suddenly in your face make you turn around and pick up the rubber band?

Maybe people feel gross about that? Like, eww, it fell on the ground, I'm not picking it up.

But wouldn't having your hair suddenly in your face make you turn around and pick up the rubber band?

Sometimes I don't notice until it's too late--if I'm biking or running and it falls off, I'm often fifty feet away before I realize I lost it. Also, yeah, if I drop the ponytail holder on a busy city street (gum! pigeon droppings! rotting food! spit! piss!), it's not going back on my head. I do try to pick them up and throw them away, though.

Maybe people feel gross about that? Like, eww, it fell on the ground, I'm not picking it up.

Ah yes, of course. Hadn't thought about that. I probably would pick it up, because I have too much hair and can't stand the thought of not having it pulled back, so the discomfort would overwhelm the ickiness factor.

When I had long hair, I went through these pretty quickly. I got the kind that were softer elastic - they didn't damage my hair but they wore out sooner. I kept four or so in my pocket and they fell out all the time because they frequently had a loose thread or a hair that hung up on something else.

I evidently lose ponytail elastics somewhere because I have to restock every couple of months. A few of mine are probably on the streets.

But wouldn't having your hair suddenly in your face make you turn around and pick up the rubber band?

Depending on where it fell I might - not on a scuzzy sidewalk or street, but maybe I would pick it up on grass. Usually I don't notice right away, or I do notice and just grab another one off of my wrist.

I frequently lost them out of my front pockets. I'd need my keys or a kleenex or a coin and wouldn't notice until later that it was gone.

I have a silver, glittery ponytail holder left from when I was in high school. I love it so much it's relegated to my ponytail holder bag. I'll occasionally take it out and look at it. But I'm not going to wear it.

I wear ponytail holders daily; sometimes 4 each (braids), mostly just one (single ponytail), sometimes 2 (pigtails). they're in my messenger bags, my pockets, on my wrist, everywhere. And I lose the damn things all. the. time.

I'd say it's a combo of many things. The one I shoved in my pocket because it got too tight and was making my head hurt? I then went back and fished for keys/change and it fell out when I wasn't looking (this happens with barrettes, too, depressingly often). Then there's the ones I chuck into the front pocket of my messenger bag where they can and do sometimes get caught and/or drop out because of putting in / taking out other things. The velcro tabs on my bags are a common culprit.

Then there's the ones that get caught on the edge of my helmet/messenger bag when I'm riding and slip out of my hair. This happens more often when I'm wearing pigtails/braids than a single ponytail, but I've lost both types, and no, I'm not as likely to notice it when I'm on the bike, especially with the breeze and helmet straps holding my hair back.

Then there's the end-of-pigtail holder that just randomly falls out for no apparent reason while I'm walking / skiing / jogging along, and I don't notice it until the braid completely unwinds like, 10 minutes later.

so yea, I'm probably responsible for littering ponytail holders about in the street. Sorry about that.

Mine definitely fall out of my bag; I think they get tangled in my keys and then fall off the keys, and since I often dig out my keys before I've reached the door I'm trying to unlock, there can be a long stretch of time where the ponytail holder can fall. I've never had one fall out of my hair, though.

My hair is very thick and wavy, so elastics generally stay put. Some people have straight, slippery hair. I doubt they notice the loss immediately, any more than I notice when the pencil I stuck in my hair an hour ago falls out.

I've dropped I don't know how many of those damn things. (The way my hair is cut, I only have a tiny little nubbin for a ponytail and so I can lose them easily for about the first month or so after a new haircut.)

Usually I've lost them if they're old and a little bit too stretchy, or in my purse and I'm digging for something else, or in a pocket. If I notice that I've lost one, I'll pick it up and throw it out, but it's rare that I notice.

Before Prissy was wrecked, I had a stash of ponytail holders on the stick. I haven't done that yet with Rosalie.

My hair is very thick and wavy, so elastics generally stay put. Some people have straight, slippery hair. I doubt they notice the loss immediately

My hair is super-straight and slippery -- it does not stay in anything very long -- but I would definitely notice an elastic falling out. My hair is also pretty long, though, so I'd have the hair-in-face thing mudpuppie mentions, which would drive me nuts pretty much immediately (I have a thing about hair on my neck; I always notice it).