It's funny how attuned you can get to your ride after several dozen hours in the saddle. Two things I've noticed lately:
a) Prior to 2013, I rode my Bianchi at between 255 to 235 lbs. As a caution against pinch flats, I always ran the tires at max pressure or even a little above. This made for a teeth rattling ride, especially on chip n' seal or on those county roads with tar stripes on every every EVERY crack (kaCHUNK-kaCHUNK-kaCHUNK for mile after mile). I've lost 45 lbs and now hover around 195. I backed the psi down and it's a different bike.
b) This morning I set out for a sprint ride, 10 mi. I tossed a G2 in the freezer for when I got back but left my water bottles and other normal nutrition at home. Lately I've been riding with 2x20oz bottles on the frame. The feeling didn't last long, but for the first several hundred yards I was amazed at how "quick" the bike felt without the bottles present. (Then I hit my warmup grind of 1mi of chip n' seal and rolling hills and my mind went elsewhere... hah).