This state is amazing it's called 'Flow' as Phoenix first mentioned earlier -- it's well documented and studied by Mihaly Csikszentmihalyi -- a must read book
Overview - https://en.wikipedia.org/wiki/Flow_(psychology)
Mihayl's great TED talk - https://www.ted.com/talks/mihaly_csiksze...anguage=en
Book - http://www.amazon.com/Flow-Psychology-Ex...0061339202
Overview - https://en.wikipedia.org/wiki/Flow_(psychology)
Mihayl's great TED talk - https://www.ted.com/talks/mihaly_csiksze...anguage=en
Book - http://www.amazon.com/Flow-Psychology-Ex...0061339202