You have the choice to carry on working on your debugger or to knock off and have some sleep or downtime. I am assuming from your choice of words that this is a personal project.
Now, imagine the same hours on someone else's tasks and according to an inflexible schedule. Would it be the same? I think not. I imagine that is what you meant by 'grinding'.
Point well taken. Even a project you're totally stimulated by, committed to, and engaged in on multiple levels can become a grind if it enters the get-it-done-or-else phase.
Now, imagine the same hours on someone else's tasks and according to an inflexible schedule. Would it be the same? I think not. I imagine that is what you meant by 'grinding'.