It's very true, joy and enthusiasm are absolutely essential for learning and creativity to happen:

"... The highest-level executive thinking, making connections, and "aha" moments of insight and creative innovation are more likely to occur in an atmosphere of... exuberant discovery, where students of all ages retain that kindergarten enthusiasm of embracing each day with the joy of learning... "

~ Dr Judy Willis, neurologist, teacher and author of 'Teaching the Brain To Read', among others;