I wonder what's Iris excuse for following Ash?
Misty's own at first was for her bike, then she forgot all about it.
Brock was to travel but then he and Ash grew close as brothers so he just came back a lot.
May was because she knew the way to the next town and then just continued traveling with him. And she also didn't wasnt to go alone.
Dawn said because they were going to the same city, but she continued following him afterwards.