Every wonderful high has a deeper shading behind it. The possibility of never-again.
It reminds me of my dad's observation that fear of heights is a misnomer for fear of depths. The incidence of falling upwards is reassuringly small, but in climbing we create the potential energy that could be converted to kinetic energy with dramatic results.
I do not understand the heathrow decision. Unless we are all to be issued with helicopters to transport us to and from the airport I cannot imagine how it would be possible to cram the trains and tubes and roads more tightly than today. Surely it's not for flying in avocados? The world is quite clearly mad.