I have to agree with everything that's been said here... I've managed to have two bad days this week, the first on Monday off-road, and the second on Tuesday commuting to work. For me it's really important to recognise that I'm having an "off day" and not push myself too hard. On days like that, I've found that trying to prove to myself that I really can ride tends to result in me throwing myself into situations that end up in lapses of confidence and crashes... So I just try to take a deep breath, think "zen" thoughts and have a slow, easy ride instead. Doing this lets me get a feel for the bike again, and hey, at least I'm outside in the fresh air. It is hard, and those days are the worst, but then there are always days that are the exact opposite, days where you get everything absolutely right and end up feeling like you're the best rider in the world!!!