David S Day 18

 5/6 and could really have gotten all 6. 

1. October 1929 :), D21. Gimme, but I don’t like this question because now Black Monday refers to the 1987 crash.
2. Hole in the wall :), D12. Very educated guess that seemed to fit the clue. I’ve seen clips of it but didn’t know the name. 
3. Guinness :), D10. Have had plenty of cans with this plastic thing in it. 
4. Gauss :), D33. Math gimme. But high D because this is by far the worst category for both my opponents.
5. Hiking the entire Appalachian trail :), D01. I’ve read it. 
6. Get going :(, D22. Ah, very gettable.