When you lose someone whom you were close to, it can be shocking. It really drives home the idea that all things are transient - even those things we take for granted as being permanent fixtures. You realize that all the little things that you obsess over are not important. Not as important as the people whom you care about and not as important as how you spend your time with, and treat, them. We're all on this ride for a limited time so make sure to enjoy it and the people who are riding with you.