Funnily enough, I came up with the term 'flow' without ever having heard of Csíkszentmihályi. For me there really is a flow. A flow of creativity, productivity. I hardly sleep in that state and if I do, I dream flashes of code. It's almost manic, I can't rest my brain until I either get it out of my system and finish what I'm doing, or something interrupts the flow
Something like a holiday, or a busy time at work or an appointment I can't get out of. Chances are if that happens, I'll never revisit the project. I can't get back into the flow and don't see the point
My svn repository is full of half finished projects, that just need polishing or debugging, or a user interface. Waiting for me to catch that elusive and ephemeral flow.