How real is it?

Last week another classmate that I graduated with passed away. I've been out of high school for just over three years and there has been five or six people from my class die. There were also several we lost while we were in high school. It's sad. Some were due to car crashes, two suicides, and this last one came by heart attack I was told. It's hard to imagine a 21 year old having a heart attack. I knew he had heart issues but had no idea it would take him away so young. All of this makes me think about life and what is important. I think again about my previous post about taking advantage of the opportunities that I have. Hmmm...