The point is, they aren't really big life events in the grand scheme of things. Much more important and memorable events will happen in peoples lifetimes than those set events that people are going on about.
When you're older (I know I know) you'll think being at the birth of your children, getting married etc will be much more important than a few pissups that are standard events in a young adults life. Thats what those events are, pissups, they aren't particularly life changing, nor are they ultimately that memorable. Young, had an excuse to get drunk. Thats it