Well... that explains everything

I rode a fairly fast paced 70 mile group ride today and bonked hard with about 10 miles to go.  I thought it was the low miles the past couple of weeks, but that didn't make much since; I should have been rested. Then, tonight... I realized I had left the bulk of my breakfast sitting by the door. I started the ride with only about 100 calories in my stomach. I had a deficit from the start! I need to pay more attention to what's by the door before I leave for the ride.