"Without thinking about it, I used to be able to fly. Now I can’t even begin to remember how I ever managed to do it."
I think this entire movie is an allegory for turning what you love into your job, and that applies to aritsts too
you see you love to do something, but then when you make it into your livelihood it removes the fun from it sometimes, especially when people don’t appreciate that you do it. Then, you lose your motivation to do it, it becomes a chore, you don’t want to do it. For Kiki, it was magic, and eventually she lost it. What brought it back wasn’t her duty to fulfill her job, but her desire to save her friend.
Always remember why you do what you do, never let anything rob you of what it is you love.