From the earliest days of my son's life, I tried to imagine the day when my son would leave home to attend college. The three of us --me, my wife, my son --spent nearly 18 years thinking and planning and talking and stressing about this event.

It was only when the time finally came for him to leave home and move half-way across the world to start college that the full weight of this momentous event hit us. What I was thinking and imagining for so many years suddenly became very real and visceral, something I could actually feel. A cocktail of emotions --pride and anticipation and excitement blended with a powerful sense of loss and separation --hit me with an intensity I didn't expect or understand until it actually happened.

Here are some lessons I've drawn from this experience, starting with one which is something I believe anyone can apply to their life or work:

There's an enormous gap between thinking about something happening and feeling it when it actually happens.

No matter how much you prepare for the day when your child leaves home for college, you can never really know what it feels like until it actually happens. It seems like a simple insight, and I'm sure I'm not the first to discover it. But I can't help but admit this one was an epiphany for me. And it's a lesson I think is applicable to other domains of my life and career. 

So much of our lives is spent thinking about and planning and worrying about future events. Planning ahead is necessary, of course. But there's a real difference between thinking about and visualizing an event in the future, and the moment when it actually begins. 

The feeling I have in the moment is almost always very different than what I had imagined it would be. This gap between thinking and feeling, between anticipation of a future event and experiencing it in the here and now, is one that I am now much more aware of.

So, what does this have to do with raising kids? What advice do I have, having arrived at the moment my wife and I anticipated--and feared --for 18 years?

Treasure every moment with your child.

The infinitely long stretch of time between the days of changing your kid's diapers and the day when you see your child move into his college dorm room suddenly becomes very compressed. Time flies, in other words, so make sure you treasure every moment you spend with your child.

Don't let work consume you.

You'll be better capable of treasuring the moments you have with your child while she is still living at home with you if you can set boundaries that ensure your work doesn't consume you. If you let it, work can easily and insidiously creep into your family time and snatch it away with late night conference calls and the constant stream of emails that scream out for your attention and quick response. 

And you don't actually have to be visibly working while you're at home to suffer from this. Just thinking and worrying about work and otherwise not being fully present and in the moment when you're with your kids can be just as bad as responding to emails.

Be a little (or a lot) less demanding. 

It's hard not to have high expectations for your child. You want only the best for them. But they know very well when you're pushing too hard or expecting too much, especially in areas where they might not be particularly strong or have little passion. Be less demanding, expect less, and just love them for who they are today and know that, over time, they will eventually discover what they're good at and what makes them happy.