What are you most likely doing when you lost track of time?

One of my goals in coaching is to help people discover and focus on what they do best.  A common question I ask is, “what are you most likely to be doing when you lose track of time?” In Drive, Daniel Pink reviews the work of Mihály Csíkszentmihályi and the theory of “flow.”
“in flow, the relationship between what a person had to do and what he could do was perfect. The challenge wasn’t too easy. Nor was it too difficult. It was a notch or two beyond his current abilities, which stretched the body and mind in a way that made the effort itself the most delicious reward. … In flow, people lived so deeply in the moment, and felt so utterly in control, that their sense of time, place and even self melted away.”
My conviction is that every person was created by God with a purpose and gifted by him with unique abilities to accomplish it.  Csíkszentmihályi’s observation of “flow” is describing what someone experiences when engaging their abilities in the pursuit of that purpose.
This is what struck me – “flow” as Pink relates it, isn’t easy.  It involves a distinct element of challenge.  It’s not overwhelming.  It’s not me trying to run a marathon today.  It’s me putting in a couple extra miles on the bike.  It’s me not playing it safe, but choosing to give myself to something just a little bigger than I can manage on my own and trusting my creator to fill in the gap.
How about you?  What will you give yourself to today that is bigger than what you know you can do?