There are certain milestones during parenthood that you record - first steps, first time they eat solid food, first successful toilet execution, first words. But the firsts run out rather quickly, and they are few and far between. If you want to be desperate you could probably record first time they curse at you, first time they pretend their phone ran out of batteries, first time they lie to you, first time you find out they smoked pot and so on. But those aren't nearly as cute.
So today, exactly one month before his 15th birthday, I noticed that my son is now taller than me. My constant litany of yelling at him to stop growing has stopped working; he is pretty short compared to most of his friends. Nature or nurture? We will never know for sure.