“Memento mori” means that “remember, you will die.” It helps to keep things in perspective. Some people hate the idea of death and try to avoid thinking about it (whether it’s their own death or others’)…but we should all contemplate death. It is inevitable. No matter how rich or poor you are, your life will eventually come to an end. When it does, how do you want to be remembered? Make sure that you act in accordance to this and don’t forget it.
One last thing – make sure that if others are depending on your salary that you set up a will and get life insurance. You never know if you’re going to get hit by a bus, get cancer, etc. When you do die (especially early or unexpectedly), it will already be an incredibly difficult time for your loved ones. Please don’t make it even harder for them by burdening them financially or not setting up a clear will, which often leads to infighting with those you love the most.