Sure I think it is healthy to speak the truth, and be who you are, and be proud of that.
At the very end of a book I can manage to work for longer stretches, but mostly, making stuff up for three hours, that's enough. I can't do any more. At the end of the day I might tinker with my morning's work and maybe write some again. But I think three hours is fine.
It only seems that there is something more important for you to do than to just quietly be yourself.