[A4] CHECK ENGINE light on-off

[RaffiTo]

HI all,

People have described a common issue with the CHECK ENGINE light coming 
on for various insignificant problems (like badly screwed gas cap).  I 
have had that happen to my 97 A4 fwd twice before.  So, when my check 
engine light came on 2 months ago I was not worried and kept on driving 
thinking I was going to go get a reading/reset at the shop I trust.  
Well, with more pressing issues on the table (you don't want the story 
of my life) and this mentioned trusted shop some distance away, I hadn't 
managed to get this done until yesterday.  Last night, when I started 
the car to drive back from work, the check engine light didn't come on!  
I was taken aback, so after arriving home (it was about a 45 mile drive) 
I restarted the engine just to see if it was not intermittent 
behaviour.  The CH. ENG. light was still off.  Then I switched the 
engine off and turned the key half way without cranking.  The light came 
on with the rest of the indicators on the dash, so I figured it is not a 
bad bulb.

Any guesses?  Should i be worried?  Happy?  Indifferent?

Thanks,

Raffi