A "gladdiction" is "glad" + "addiction". A positive obsession. Too often, we use the words "addiction" and "obsession" pejoratively, and they do have a lot of valid, negative meanings (like being a "drug addict") which rightfully get called out. The good side doesn't get risen enough, and that's where all this is lopsided.

Gladdicted people do incredible things. They make viral Internet videos which touch thousands, if not millions of lives. They (like Dean Kamen and Richard Branson) invent life-changing inventions and businesses which refresh human societies, not to mention spend years of their lives solving math & science problems to unlock barriers which humankind at large benefits from. Gladdicted peeps also collect intense amounts of memorabilia, serving as consultants on Star Trek and other shows as uberfans. They also win the Olympics, many times over.

Sure, maybe "gladdiction" is just another way of saying "passionate". But look closer, and you'll see a Venn diagram where the two only partially overlap: it takes passion to get excited about doing something worth doing, but one is only gladdicted when they're in action!