Me and DIY Don't See Eye-to-Eye

I seem to have this curse with the physical world, or at least some sort of reverse Midas touch. Anything manual or mechanical I touch seems to break without me even trying.

So, I was quite pleased with myself after spending about 6 hours today sanding and glossing the window frames in my conservatory, having spent about 8 hours last weekend sanding and undercoating.

That was, until just now when I went out there to inspect my handiwork. From a distance I noticed it didn't really have the sheen I was expecting, and as I got closer a curious thought crossed my mind.

"Why has that gloss dried looking like undercoat?"

The answer is, of course, that I've only accidentally gone and put a second coat of undercoat on instead of gloss.

Grrrrr...