man, I'm glad you started this thread! I thought I was the only one who looked down to see if their tire was flat or if the brakes were rubbing.
I'm with you 100% on the afternoon ride being harder... save for the one day when I did eat about 1 1/2 hours before I went home, and then I sailed home like nobody's business. you'd think I'd remember that lesson, but alas, work beacons, and I haven't time to remember to eat like that daily.