It's a familiar feeling. Two weeks ago you had your three hour cross country flight over Goldendale. One week ago you drove to Summer Lake and it rained the whole time. This week is your birthday and all of your favorite old friends are visiting from out of state. The sky is clear, the soaring index is great, and the wind is uphill at 9 mph at your favorite launch. So you complain to your friends: "Why did my birthday have to come on this weekend? I never get to fly!" Their eyes glaze over and they start muttering to each other about how boring you've become.

So why is flying so addicting? In long car rides home we've all discussed the sublimity of flying over a flock of birds; the kinesthetic glory of watching the full horizon climb up from behind your launch; the fascination with being able to picture what the air is doing; the intellectual thrill of solving the problem of flying from point A to point B; and the motor accomplishment; the sheer joy of achieving one of childhood's earliest and most pervasive dreams.

There are however, more prosaic situational factors which push us into becoming air junkies, and recognizing these aspects may save many a friendship, conceivably a few jobs, which in the long, long run are vastly more important than the airtime.

Foremost among these considerations is pure Skinnerian variable ratio reinforcement. Classic behavioral experiments show that when you train a chicken to peck a spot for a pellet of food, and then vary the ratio of the number of pecks it takes to get the food, after a while the bird will peck forever, more and more frantically, until it drops from exhaustion. This is the principle behind compulsive gambling. Even if you know the odds are against you, you also know you might win big. And if you do win big one time, you'll never stop trying to do it again.

Think about it. While you're driving two hours to your site, you don't know if you'll even unpack your glider, and even as your feet leave the ground, you don't know if your ride will be a few minutes or a few hours. You only know that gravity always pulls you down, but you might win big.

The second force is the herd phenomenon. Flying is surprisingly social, considering how alone you are on top of that big thermal. We're always calling each other and inviting each other out to play. We're intensely interested in what happened any time someone else flies well or tries a new site. We badly want to keep up with the group (so to speak). For some of us, flying has involved us more deeply in communal activity than we've been since school.

Perhaps the most mundane problem is our worry about keeping current. We fret about getting out of practice. In our group this is actually stressed quite a bit. While there is some validity to this concern, it's a good idea to reflect that a little hop and pop practice in a city park can make us safe flyers again.

The fourth issue has to do with weather consciousness. A few weeks ago I had just ridden my bike home from work. The phone rang; it was my brother-in-law, not a flyer, asking some social questions. In passing he mentioned how windy it was at his house and wondered if it was blowing where I was. East at 18, gusts to 25, I replied without a touch of self-consciousness.

We subconsciously monitor the forecast and the microclimate continuously and in incredible detail. Just listen to two pilots talk for more than a few minutes. Or think about what your first question is when your parents-in-law come back from the beach. (Was it windy?) Being this acutely aware of the weather is necessary to fly successfully, but it makes us frantic when its good and we can't go, especially when we know others are going.