Your training suggests you could do sub-21 for (not-too-hilly) 5k. Maybe you just needed a day off before this.
Like to think so. It occurred standing around for 20' in singlet in eventual 58 deg rain (preceded by more waiting but sl more covered) for the governor to fire the gun possibly had an effect I discounted - but all those kids etc that ran by had some kind of effect too..:)