Blue Sky Thinking....

A beautiful day today, clear, cold and a big blue sky - which got me wondering. If 'Blue Sky Thinking' means, brain storming big ideas , could you have 'Grey Sky Thinking' - thinking about depressing things?

'Sky Thinking' could become the latest business technique

Mackerel Sky Thinking - you could only think of fishy things
Golden Sky Thinking - jewelery based ideas
Rainy Sky Thinking - water based thoughts only.

Oh dear! - I don't think the drugs are working anymore.