years ago, i bought a 750/4 chopper out of the paper after looking at it in near dark, it was slightly damaged (having been hit by a car while parked) but all the basics seemed ok so i coughed up and bought it.
when i got it home and had a good look in daylight, there was nothing good about it at all, the forks were rusted and bent, the motor was filthy/corroded and turned out to have a worse gearbox than the bike i already had, the wiring was rubbish, the cables and oil/brake hoses were cracked/frayed/perished/leaking, all the bodywork was damaged and rusty and best of all when we took the tank off, there was a large hose clamp holding the broken frame backbone together.......
did i learn anything from the experience...well i'd like to think i'd have second thoughts before buying another bike in the dark, stoned and from a trailer park. it's true i've bought bikes since then under the influence of mind altering drugs but none of them turned out as bad as that POS (mind you it would have been near impossible to avoid doing anything while i was stoned, i spent about 15 years permanently bent, if i was awake, i was ripped, damn good fun while it lasted)