I make a point of saying "I love you" to my wife every morning when she leaves for work and I sms her again as soon as I leave. As blunomore said "can you be sure you will see that person alive ever again?"
My wife and I have unfortunately been in the position where we were held up at gun point at our house, luckily nothing happened as I was able to get us into the house quickly enough and slam the Maxidoor shut, I always laughed at their ads with the women running, since it happened to me I appreciate that ad. The visitor was still able to get their quickly enough to shove his 9mm through and put it against my chest and tell me to open up but we were inside and nothing was going to make me put my wife in danger.
As I said though we got through it unscathed but since then each day is appreciated and saying "I love you" takes on a very new meaning.