In a freak accdentident today my cousin was killed (he was a BMX bike racer). He was 33. He has two kids under the age of 7 (I can't remember). There is no “tomorrow” for Sean. Sean always thought he was invincible, and a helmet wouldn't have saved him in this case (his chest slamed into another guys handlebars). How doesn't really matter. He's gone. He was here yesterday, and now he's not.
So if you have kids, hug them a little tighter tonight. If you haven't talked to your parents lately, call them now. If you are arguing with someone, holding a grudge, put down your pride and pick up the phone.
Tomorrow is not guaranteed.