The last terrorist attack in Egypt happened in Dohab 2 1/2 years ago. Another place that I've visited.
It's not an everyday event that a bomb explodes in Egypt, but it happens every now and then. Truthfully, a foreigner has way better chances getting killed in Egypt crossing the street than by a bomb. But nonetheless, the looming possibility of a bomb exploding is scary-- especially when you put it in relative terms, I was in the exact place only 2 days before the explosion.
You never know what to expect in Egypt. Anything can happen. And, this is one of those things.
I am at a loss of words to express the risks and dangers of living in Egypt, so I'll refer to the Egyptian's own words: Alhamdullah salema -- الحمد الله سلمة -- translated, thank God for our well-being. It's a phrase you'll hear whenever you return from a trip away from home, after a near accident in a taxi, or at those moments when your life flashes before your eyes (which is not too uncommon).