when you wake up on a Monday morning and you really dont want to go to school/work that day so you dont.

of course you could say "Monday Sickness" any day of the week.

When you eat dirt for the first time and leave your family to build a shack in the woods

A feeling experienced by (But not limited to,) high school aged individuals on the first day of every school week (Monday).
Common symptoms include:
Lowered brain functions,
Bad Temper,
Stress,
and an overall feeling of human (Or otherwise) excrement.