I've long been skeptical of the "judge your seriousness by how MANY hours you work" mentality that's so common here in the USA. Ultimately, it's simply not human to be truly consistent, and one can see a whole frustrating variety of results within the same exact span of time on any given day. I'm glad you're forthright about this, because more aspiring and blossoming writers need to give themselves permission to work fewer/non-traditional hours if they want to!