Random things I've noticed:

• If your bike is making a persistent rattling sound, the derailleurs aren't lined up properly - wiggle the gear levers around until the sound goes away. This is why I hate bikes with indexed gears, by the way.
• If your bike is making a periodic rattling sound (i.e. every stroke of the pedals) one of your gears is crooked. It's just going to suck until you have enough cash to go to the bike repair shop.
• If your bike is getting really hard to pedal and your foot is being squeezed to death, your shoelace is caught in the chainwheel. Stop immediately and untangle it, stupid.
• Rabbits are stupid.
• Self-control goes down the drain when I'm reading a Patrick O'Brian novel. Or a Lois McMaster Bujold novel. Or a Terry Pratchett novel. Et cetera.