For me it means that I feel like I'm a different person from time to time. My personality, likes, dislikes, values, beliefs change a lot. Today I'm sure I want to be a yoga teacher, tomorrow I want to work with children, then I want to make websites, then I am going on holiday and after a long flight I'm checking out careers in aviation. Maybe it doesn't change every day but it does often.
I usually end up wanting to change jobs often though in reality I stick to it but resent it. Then I like it again. Then resent it again.
I buy hobby materials and then I want to do a completely different hobby, I dive into it, it's like what I wanna do forever. Then I just don't care anymore about it.
I'm also unsure about my sexual orientation somewhat...
My self image changes a lot based on my environment and people around me as well. Some call this "absorbing" other peoples stuff, identity, etc. Sometimes I feel like I am getting defined through others. Like I'd disappear without being defined by or attached in a way to other people.
Today I describe myself in one way, tomorrow in another way. There are some relatively stable characteristics though about myself, and I'm trying not to forget those.

This is how I see it/ experience it, but I suppose others might have slightly different perspective on this.