Also, you may have a job where none of your responsibilities are unique to you, but that's not often the case outside of some types of shift work. If I take a vacation or sick days, I have catching up to do. No one is going to step in for a couple of days and pickup where I left off on a project I've been working on for 3 months.

As for missing school, my kids go to typical mediocre public schools. When a student is struggling, they're given a little extra help. When they miss because they're sick, they're given plenty of time to makeup the work. And if a student is struggling so much that they can't reasonably move on to the next year's more complex material, the school literally devotes and extra year if resources to