I used to work for Covey Leadership Center. Stephen Covey liked lighthouses. For him they were a symbol of stability. The lighthouse would faithfully stand there warning ships to stay away from the rocks, from danger.
For me, a lighthouse is instead a symbol of transition. It's not that people on boats can't come up to land. In fact, getting onto land is probably the whole purpose of the trip they've made by sea. The lighthouse instead of warning them to stay away signals that it's time for a transition. The lesson is, what has brought you this far won't work for the next stage of your travel. You'll have to get out of your ship and into a train or car or even onto your own two feet. You have options but the ship isn't one of them. You've reached land now and can't expect to float over this next bit.
This is what happens when you leave behind childhood for your teen years, when you leave the single life behind for the married life, become a parent ... well, so many transitions require us to get outside of ourselves and enter into something different, to become someone else.
Lighthouses aren't secrets. It's almost cliche to talk about how a life changes when you become a parent, or a grad student for instance. It's not hard to see a lighthouse. But the message of the lighthouse is not always so clear. Lighthouses don't warn you back to sea. They simply say that a transition is coming and you need to pay closer attention than you have. You even have your choice of new vessels; there are a variety of choices about how to navigate this new surface. You have a variety of choices but the vessel you've been in up until now is not one of them. Who you've been is no longer an option.