Everybody in every sport has those days- and you'll have more. It's really hard to accept that the magic carpet ride isn't happening and the universe is conspiring against you, but those days are nessesary, 'cause wouldn't the good rides be meaningless with no spastic struggles to point them up?
Those bad days are really valuable though because you do have to struggle, and talk yourself through technique, and when the going is just break down and cry awful is when you become the better rider/ skier/ skater/ whatever. I had a famous coach come to town years ago for a three day camp (nother sport) and it was just the most horrible three days of my life- he worked us till we dropped. I went home and cried myself to sleep, I couldn't do anything right. When he left on Sunday he said the body learns and adapts when it's pushed hardest, that technique and combinations and all sorts of neat tricks get learned that way. So fifteen years later, I still surprise myself and a lot of other people with what comes out of that awful weekend. I'm retired from that sport, not supposed to play 'cause of knee damage but I go by anyway once in a while. The body remembers.
Spastic days are just part of getting to the next level- just don't do anything really risky, My spastic days on Miss Bike (cross country) seem to end in a headplant or require a lot of stitches, don't reccomend it. Go to the park and ride drills, learn some of eNd Overends neat tricks, talk out loud and coach yourself. Also good for getting home, and by the time you ride a MT bike, you don't care what the neighbors think anyway do you?
There's an easy explanation, too- you could just be tired. That'll make you ride like a sack of lead. I've been out for my fix before and been a complete mess when I should have gone for a drink instead; Even the super fit need recovery time, and get plain tired. Try not to beat yourself up over it. I bet even eagles have bad flying days. I heard one whining in the woods one day, not at all like the TV sign off image. Poor girl must have had PMS she was squawkin and bawlin so bad.

missliz