Why do i move back and forth from subject to suject during a conversation?!

Why do i move back and forth from subject to suject during a conversation?

ive noticed that when im having a conversation, i tend to go back and forth on a subject..for example me and friend were talking about sports, and outta nowhere i started talking about cars..i always do this ..any ideas on what causes me to do this?

2 weeks ago
im also easily stressed and i have a tendency to daydream alot and i make alot of silly mistakes when performing tasks at work..

well my mom says that there are two kinds of people, groupers and stringers. The groupers like to talk about one thing and finish it, then talk about another subject and finish it, like nice little groups. Then there are stringers, they go from one subject to another subject, then maybe back to the first subject, like maybe a big spider web,they just go with the flow. I'm a stringer, and my whole family are groupers, they can get frustrated.
It just means you are a stringer, its not a mental problem or anything, its just the way you think.