How does ADHD causes this and what do you mean with dead? I'm curious, as certain appointments also cause me to "lose" a day. I'm also seemingly incapable to do

How does ADHD causes this and what do you mean with dead? I'm curious, as certain appointments also cause me to "lose" a day. I'm also seemingly incapable to do much else with my time, if there is something I should be doing. (I really like to learn about x, but my job requires me to get better as y, which I don't care for. I end up learning neither x nor y).