Scheduling

Why do I insist in having this picture in my head of the schedule I could manage, if I were, I dunno, a robot?  I know that there are 18 usable hours in the day, and theoretically if I work for 11 of them I could get 5 hours of other things done in the day, but, well, it never happens.  Pesky things like needing to eat, go to the bathroom, actually converse with human beings so they remember I exist - all of these foul up the fantasy I have that I can, in addition to those eleven hours of work (two part time jobs because I didn't get the job in my field I hoped for this summer so I'm doing part time entry level in field, volunteering, and working a coffee shop job), I should be able to spend:
1 hr working out
1 hr practicing foreign languages
1 hr writing
1 hr cleaning
1 hr maintaining contacts (email, listservs, notes to others, phone calls to family etc)

2 hrs work related transit.

You'll see the problem with this schedule much faster than me, right?  (Besides it only ever leaving a max of 6 hours for sleeping?)
It doesn't include:
personal grooming
cooking
eating
dressing/undressing/ironing
reading
or a whole bunch of other things.

Which is fine, we're not superhuman here.  But why oh why do I persist in feeling so GUILTY that I can't do the 5 hours of things above in the days when I work 11 hours?

*grr*