allow me to explain. 

Normal Destroy Dick December is where you nut as many times that day according to the date. So on the 1st December you nut once, 2nd December you nut twice, etc. You may have heard of other, harder versions such as adding the dates up, so day one is 1, day two is 1 + 2, etc. But extreme Destroy Dick December is where you nut as many times that day according to the date *factorial*.

On Day 1 it's not so bad. It's just 1, so you nut once. Day 2 isn't bad either, since 1 x 2 = 2. Day 3, 1 x 2 x 3 = 6, so a little challenging but nothing too major. Day 4 is where it really starts though. 4! is 24. So that's nutting once every hour. Day 5 gets worse. 5! is 120. 120 / 24 = 5, which means you nut 5 times per hour. Day 6: 720 times per day. That translates to 30 times per hour or once every 2 minutes. Maybe possible if you've taken copious amounts of every stimulant drug on the planet.

Day 7 is where you have to start rejecting your humanity. 7! = 5040. 5040 / 24 = 210. 210 / 60 = 3.5. 60 / 3.5 is about 17, so that's nutting once every 17 seconds.

Day 8, oh god please stop. 8! is 40320, that divided over 24 hours is 1680 times per hour. that / 60 is 28 times per minute. Per fucking minute. So once every \~2.1 seconds, you have to nut. This is getting insane. 

You can see the pattern here. By December 31st you'd be a dehydrated corpse, but if you somehow survived: 

31! is 8.22 x 10\^33.  

That / 24 is 3.43 x 10\^32. 

That / 60 is 5.71 x 10\^30. 

Divide by 60 again and you get 9.52 x 10\^28. 

Divide by 1000 and it's 9.52 x 10\^25 times. Every millisecond. An incomprehensibly large number of nuts every millisecond, if someone could please calculate the amount of energy required for that it'd be greatly appreciated, i'm done with this