Like one person said, I didn't really ride my horses in tack. It was just hop on and go.
Another said they were lazy to put tack on, yup, that was me.
I use to work at a horse camp/ranch and I'd saddle and unsaddle horses all day long. The last thing I wanted to do was saddle my horse and go for a ride.
Like another, I've done a lot of stupid things on horses. I should probably have more broken bones then I've had, but I was fortunate. I didn't always wear my helmet. Infact, I think I rarely wore a helmet.
It's quite fun, very exciting. It gets your heart racing, your adrenaline pumping. Grab mane, that's all I can say.
It's hard to stop, once you get going full speed. I suggest check and release to slow down, instead of dead stoping.
If you have a helmet, wear it. If you don't wear one, well you know what could happen if you fall and aren't wearing one.