It's when I come across something like this:
Late one recent hot northern evening I was turning off the lights and saw this moth flitting around the house and I quickly became enthralled by it's patterns and colours.
The only camera I could lay my hands on was our little family Canon Cybershot. So it was direct flash and trying to figure out how the macro worked as I followed the moth around (it was still around next morning, but I only got a shot of its upper wings before it flew away into the garden).
But those patterns - the black and cream on it's upper wings and then the wonderful orange/red on it's under-wings. I just felt like I need to design a shirt or a dress or a book cover or fabric wall coverings or something - to take those patterns and colours and translate them into something else. Of course I'm not what you might call a designer, so I didn't... (you really don't want to see me draw or even try and design the dogs house).
But the pattern and colour still flits around in my mind.
BTW, it's a Tiger Moth.