How does one know when to stop?

I had a thought in my head last night-
As I laid in bed, eyes open, lights out,
It came to me, and I was excited.
I've lost it now,
I couldn't be fucked to turn on the lights, reach for a pen, and write it down.
So I lost the start of something that would have been good.
I'd suck as a writer.

Rage.
It drives you to such lengths.
I kicked the quilt off my toes
I hissed with such contempt.
Eyes filled with white-hot malice.

Last night I dreamt a strange dream.
Driving through Kew in Singapore (the unconscious still flutters between here and there),
To meet M for an iced latte at Starbucks.
After Mr Lim's (manager on site) refusal to lend me any service
There was a loud altercation.
I drove off,
Then drove back again as I was dissatisfied with the lack of resolution.
This time I yelled louder, mad with fury.
When I turned to leave
There was a face I hadn't seen in years.
I never knew him, really.
We never spoke, and he hasn't been on my mind since 1997.
All through the dream he was nameless (I only remembered it in the shower).
He was reclusive, in the chi-chi apartment dad had paid for.
There was a newspaper clipping with his picture "Man sentenced to 6 months for stealing truck".
He cooked chicken in the microwave oven and had a cat.
I stayed the night and forgot to feed Milo (who in the dream, took the form of a silky terrier I had back in Singapore).
A fallen soul, I loved him.
I made all this up in my sleep
For I didn't know him.