It is certainly appropriate to celebrate a person's life instead of mourning their death. In fact, many people choose to have a celebration of life after they die instead of a traditional funeral. It is a personal choice that depends on the preferences of the individual and their loved ones. Some people feel that celebrating a life affirms the positive aspects of existence, while others find it difficult to think about happy memories when they are grieving. In the end, there is no wrong answer, and both approaches are respected by many people.