You should read Flow by Mihály Csíkszentmihályi. Flow is defined as completely focused motivation. http://en.wikipedia.org/wiki/Flow_(psychology)

The research states that flow is achieved by balancing skill and challenge. http://en.wikipedia.org/wiki/Flow_(psychology)#Mechanism_of_...

With respect to the original author, it sounds like he hasn't been far enough along in his career to be humbled by a hard problem.