What do you do the day after a terrorist attack occurs in your city? Well, the sun was shining, it was 18 degrees (Celsius, you Brits and Yanks) and it was a Saturday. So I went for a walk, and people were out with their dogs and playing with their kids and riding their bicycles and strolling hand-in-hand with their loved ones and laughing. And I met friends at a cafe, and we talked about books and movies. We didn't talk about politics, and we didn't talk about the bombing.

But it was there, hanging over us, unmentioned but present.

Then in the evening my friend Chani called me, and we talked about work and her son's upcoming bar mitzvah. Suddenly I told her that I'd let my guard down. I had lost the ability to shrug off the bombings, and I didn't think I had the energy to deal with the rollercoaster of emotions again - the adrenalin rush and the grief and the fear.

But most of all, I am afraid of the numbness. Because when unspeakable events occur on a regular basis, survival mode kicks in: you can't deal with those constant questions about meaning, so you don't. You become numb. And that means that you lose a bit of your humanity. Because if you cry over every person who is killed, then you go cuckoo. But if you don't cry, then you've lost something important. Empathy. Humanity.

How long does it take for people to become tired of killing? It took the Lebanese - what - 17 years? And the (former) Yugoslavians - eight years? I guess four years isn't enough for some people.

But it's way more than enough for me. I'm tired.