Protip here; don't eat a buffalo chicken calzone the night before an 18 mile run. Luckily I can swing by the Mobil bathroom at mile 6. And 12. And 18. Let that be a lesson to you all.
Next week is the New Bedford half so a little reduction in the mileage this coming week. After that it starts to get interesting. 20 miles has always been a dividing line in my head. Anything up to 19 still starts with a one so it just doesn't have the same impact as 20. 10 is 15 which is 19.
This is the same phenomenom that has us seeing prices in odd ways. $199 is still in the hundred range so we think, "Hey, it's only a hundred bucks!". Not, "Holy jeebus, that's two hundred dollars!". That's what 20 miles does to me; it makes me say "Jeebus that's freakin' long." And then I have a buffalo chicken calzone for dinner.