Fixing bugs requires no *initiative* , no decision making, no long term planning. Those are the hard things about work. For example, I often think longingly of jobs like being a farmer or doing manual labor, or even being in the army, because even though I'm sure they would be very very hard, they don't require personal initiative - you know what you have to do each day and you do it.
The hardest thing is when it's totally up to you and it's also a bit unclear exactly what you should do. I guess the clearest example of this in the popular imagination is the author facing a blank page. When you have to choose your own path and personally motivate yourself to take the next step - when it's unclear that's even the right step - that's the hardest work there is. (this is part of why so many indie game devs never finish).
This morning I was thinking I miss that feeling of "fighting fires" that you get at normal game companies. Some days you would come in and people would keep coming to you with a bug or some feature they desperately needed. You never had to choose what to do for yourself, you just say "okay, I'll fix that" "okay, I'll add that feature" and then you just button down and do it.