First, this is a message to middle school kids. It is a solid message: Determine what you love to do and give it all you have.
It is true that what you achieve in that pursuit will be mitigated by your actual talent for it, life circumstances, responsibilities and resources, not to mention luck. But even if you can't make a living at it or even get to it very often, doing what you love for its own sake will make your life more satisfying than not.
True?