I was interested in a lot of crazy stuff as a child. There was a time when I was obsessed with locks and keys, another when I was passionately interested in piano. For years I worshiped Super Mario, even though the family didn’t have a Nintendo– I guess if we’d had one I would’ve grown tired of him much sooner 
What kinds of childhood phases did you go through? We all had some pretty exotic interests. But why does it have to stop at childhood? Adulthood phases are like childhood phases, except you go through them as an adult.
An adulthood phase is when something new enters your reality and begins to dominate it for awhile. It’s not quite the same thing as a hobby, though they are similar. A hobby is like glowing embers which smolder on for years and years. A phase, on the other hand, is a shining flame which burns brightly for one or two years at the most, sometimes no more than a month or a week. But while you’re in the phase, it is a lifestyle. You think about it before bed at night and it enters into your very dreams.
When I was a senior undergrad, I went through an Urban Exploration phase. More recently, I’ve had a burning interest in technology, futurism, transhumanism, and that sort of stuff. When I was in the Air Force, I went through a Silmarillion phase, and that illustrates an important principle: nothing is too obscure for you to phase through
One of the differences between the childhood phase and the adulthood phase is that, as an adult, you have a lot more power to pursue your interest. You’ve got money to spend. You can finally stay up past your bedtime whenever you want. You’ve got stronger muscles to apply toward the physical or practical aspects of your fixation. Your mind is enhanced by decades of life experience and you can learn and master theoretical knowledge much faster than you could as a kid.
As you go through more phases, not only do you pick up knowledge about each individual area. In the background, you practice the abstract meta-skill of going through phases in general. You get better at navigating the world through the eyes of a newbie– and everyone should strive to be in newbie mode, because when you’re not in newbie mode, you’re not learning.
Maybe we were really onto something when we were kids. Phasing is a very efficient way to maximize total learning. In any field, there’s a lot of rapid growth when you first get into it. Later on, when you’ve mastered the field and when you become an expert, the learning process levels out a lot. You get less and less ROI, having to study for months and even then you’re never surprised by anything any more. Unless you’re paid to be a mega-super-expert, it’s probably best to move on to the next phase.
There’s a word for being out-of-phase: “Bored.” If you ever find yourself wandering aimlessly around the house, boredly browsing YouTube, staring into the fridge for minutes at a time without eating anything… then you my friend, need to go through another adulthood phase. Need some ideas? Try the List of Reality Escapes. There’s bound to be something on that list you can get yourself obsessed with for the next couple months
FURTHER READING
Arbitrary Leadership
Emotional Knowledge
Reinventing the Wheel