You're interested in drawing, you love to draw. Nothing else exists once you're in front of your canvas. You can draw for hours, never get tired, forget to eat, time flies and you don't notice. It's your passion. You can't think of doing anything else in the whole wide world.
So you draw and study and improve and go to school and learn and get better and now you need to make money.
You can't think of anything else to do but to draw so you look for jobs where you can draw or you start putting your work out in the world on YouTube or Behance.
Once it's not longer a hobby, and becomes something that people pay you for, it changes.
You find out there are all these other things that you much do to support the thing you love that sometimes get in the way or drain all your time and energy and ends up keeping you from the thing you want to do which is to draw.
So you have to write a script for YouTube now, have a camera, have lighting, have fast internet, fight with your computer, edit the videos, look at analytics, do B-roll, create a content schedule, manage money and so on.
There's always something that comes with the work your want to do that you don't really care about but somehow have to do it.
The web developer wants to just code but now she has to sit in a meeting and endure endless back and forth of two people saying the same thing with different words and not realizing it. All she wants to do is code and ship great products.
There's always something more.
If you think you'll just do the thing you love and nothing else. I'll break your heart now, it's not going to happen.
Factor in time and energy for all the other things you will have to do in addition to the thing you love.
When I come home from work, I'm usually exhausted but once I can create, I'm energized. I just want to create but I'm forced to deal with people all day.
There's always something more.