How much time do we really have?

One never really knows ...
A co-worker of mine passed away very suddenly this morning. I had just talked to her yesterday. She said hi. I said hi. We were passing in the hall. She always said hello even if she was in the middle of conversation. She once gave me a little card with a 'get a free coffee' coupon inside of it for getting a project done for her ahead of schedule. Yesterday I saw her and now she's dead. She was only 55. She had a family. No one got a chance to say goodbye to her. She was preparing for a normal work day, had a massive heart attack and was rushed to the ER where she was pronounced dead. Gone! End of story! Just like that...
When something like this happens to someone you know, it makes you realize how silly and stupid the little things you worry about every day are. It makes silly arguements seem even more asinine. It's odd how things keep moving when something like this happens. It makes you realize how insignificant your life really is in the grand scheme of things. I mean, what's the point of all of the stuff we do in our lives? (I know, age-old question, right?)
I know this feeling of goodwill that I have right now will fade with time, but for now I want to be good and kind to people, because you just never know when their number (or yours for that matter) will be up.