The biggest thing that gets in the way when you homeschool?
If the kids are in school 8 hours a day it leaves time open to run that emergency errand, take care of the unexpected family need, or tend to one sick child (or one sick mommy!) at home while the rest of the troupe is gone for the day. Homeschoolers have no such time. All of life's little emergencies must be solved, on the fly, with all children in tow.
This can get complicated.
More traditional homeschoolers may be able to sit the kids down with workbooks and squeeze in a spare minute-and of course, as unschoolers our family totally rocks the educational TV-but let's face it. Kids can only sit and watch/work for so long and the unexpected usually doesn't come at you on a schedule.
So what do you do as a homeschooling parent? I say go with it.
My theory is that chaos can be educational on a whole new level. Not that I recommend you give your home over to anarchy a-la Lord of the Flies...but a kid can learn a lot from some of life's little surprises.
Mommy is sick? Not to worry. Well, okay, worry a little. Things are bound to go undone, and kids are bound to go a little nuts when the cat is away...or sick as the case may be...but enlisting your kids in little ways can help them learn compassion and empathy (for poor sick Mommy), independence (as they do more things for themselves while you rest), and it's easy to add in some more of the 'educational' type knowledge as well. Have your kids help you brew some peppermint tea. Let the older ones organize a quiet educational game for the little ones. Discuss microbiology and pathology over a lozenge and some Kleenex.
Have an unexpected errand? Can you say 'Car Bingo'? Older kids can estimate the time it will take to complete the errand based on mileage and rate of travel. Or, as you're getting ready, have the kids make To Do lists of their very own which include both your daily errands and activities they want to do when you get home. That's good practice for writing and organization skills, as well as gives them something to do while you're out ("Alright kids, check off 'get toilet snake at Home Depot' ") and reminds them of what they have to look forward to when you get home.
The trick to stopping life's interruptions into homeschooling (in my experience) is not to try to stop life from happening, but rather to wrestle every educational moment and tidbit you can out of the unexpected.
If worst comes to worst they can always learn the fine art of "Heads Up 7-Up".