Ok have a couple here:
* had two students whose parents didn't want to pay for day care. They would show up at class and stay the whole day. At one point they came without uniforms even and just sat outside. We asked, are you doing class? "NO, our mom just told us to wait here."
-- we called and told them we're not qualified or staffed or paid to babysit their children. If they abandon them again at our front door, we would call child protective services. It worked.
Second one isn't really a learning problem, it's a behavioral one:
* We had a 13 yr old student who would periodically defecate on the mat. Yes I said DEFECATE on the mat. We would just find it there and not know who did it. One day during class we saw this kid turn, shake his leg, and drop a "poo" on the mat out the bottom of his gi pants. My instructor lost it. I swear there was steam coming out of his ears.
He took him in the office and promptly excused him from ever taking classes again.
edit- in retrospect, I guess they were both behavioral problems. ~Corwin