I enjoy noting the first time something happened. As a father, there's some obvious firsts that will typically be accomplished by your firstborn. First child to crawl, first child to walk, first child to speak, first child to graduate high school, and so on.
The firstborn doesn't get to hog all the firsts... many fall to the second-born, or third-born, and yes, in my case, the fourth-born.
Last weekend, when I returned from my daily bike ride, my youngest daughter asked me if we could go on a bike ride. So we did! This marked the first time a child of mine biked in the month of February!