I don’t mean to be depressing. But you know when you enter an annual recurring event in your calendar and the calendar asks you when the event ends? Well, I like to think about that whenever I enter birthdays.

In physics there are the related concepts of potential and kinetic energy. Potential energy is all of the latent energy that is stored inside of a thing waiting to do something. Kinetic energy is the energy a thing has when it’s in motion. You increase an egg’s potential energy as you carry it to the top of a building. And when you drop it from the roof, the potential energy in it is gradually converted into kinetic energy as it accelerates towards the earth. The potential energy is finally spent when it hits the ground and explodes.

As a father, I can sympathize with the egg.

Every new day is full of potential. But some days I get out of bed and the kids go mad and I go mad and we start falling immediately. On those days I feel that my relationship with them is not unlike Gandalf’s relationship with the Balrog. We fall together, struggling. And as we fall, I can see blurry visions of missed opportunities whoosh past, alternate paths we could take and explore if we could just float for a little while. But on those days we have nothing but fathomless black chaos beneath us.

Life is like that, too, it seems. Full of potential and slow-moving when we are born, we gain momentum as we age and grow and learn. That momentum is useful. But it also prevents us from changing course as quickly as we’d like. And we find our potential shrinking as we plummet through life towards the inevitable.

Lately I’ve started to accept the idea that a man can’t be a person’s father and their friend at the same time. At least, not while that person is a child. Of course one can be friendly—but that’s not the same thing at all. What a child wants and what a child needs are very often not the same thing. Friends don’t send friends to their rooms when they misbehave. Maybe true friendship can’t come until the child can stand on his own, when the father accepts the child as a man and the child realizes the father is only a man.

It’s so much more important to be their father. But I’d like to be my children’s friend one day, to be resurrected on the mountain as John the White. In a world of potential, it’s something to hope for.