On Tisha baAv you can't

1. eat

2. wash oneself

3. anoint oneself

4. marital relation

5. wearing leather shoes

6. sit on a chair

7. Torah study

8. greeting people with a blessing

9. conducting business

10. going on a pleasure trip. etc.

So my question is, what are you supposed (or what do people) do for 25 Hours. Besides maybe 3-5 hours of davening and 8-9 hours of sleep coming out to about 13 hours of...