These days we are considered to live in times, when many people are regularly busy. Even though a variety of them say they don’t have time for diverse activities, in the reality they tend to waste their time. After some time spent on analysis in terms of what they do with their time they mostly realize that it is wasted in significant percentage on various activities.
When you're a grown-up, plenty of times during your entire life, you've many of reasons to celebrate. Birthday of your kid, Bar Mitsvah, anniversary. In that situation, many of us like to organize a party.