One is fear-driven, and thus highly dependent on other people's granting of validation. The other is self-generated spirited enjoyment of anything one might do, with little dependance on the validation provided by other people.

Essentially, the difference is to do with which set of emotions are being dominant: loneliness/ validation/ approval-seeking versus enjoyment/ spiritedness/ play.

Think of the fun inherent in hobbyist programming, but extended to life at large.