It can change, but as a solo dev, the hours I spend on my game are comparable to a 2nd full time job. So it does take a lot of my time working on Terrene.
But I don't mind, since I enjoy making this game.
If you ever want to make your own game, just start small and learn the basics you need, (like drawing, programming, writing etc.)
Can be a bit daunting at first, but is rewarding once you learn it.