My stepson told me once about an episode of Family Guy or The Simpsons or some cartoon in which one of the characters was easily (and often) distracted saying "Oooh look, something shiny". At the time he was helping me decide which used car to buy, and every time I went to the car lot, I'd see something else I wanted to test drive...
I admit to doing the same thing in crafting. It's the excitement of creativity that must release those endorphins. Every year at this time (mid-year), I try to stop new projects and finish several.
But I haven't yet bought the same fabric twice.