What are some things people think are cool but really arent?

A vehicle is defined as something used to transport people and/or goods.

So yes, a bicycle is a vehicle. Arguably legs/the body are also a vehicle for you.

Yes, a bicycle is a vehicle.
I have no idea why it shouldn't be. It's a machine you use for transportation.
Many of them even have motors or engines, even though that's not a requirement.

At least in Japan, a bicycle is legally a vehicle. It has some special carveouts compared to even scooters and the like, but it's a vehicle