At birth there are usually more males than females. Around adulthood age they are roughly equal, and around our death there are way more females than males.

Another one, kinda romantic as well. Most life long couples, when one of them dies due to old age, the other one follows soon. Despite women having a longer life span than men.

Another interesting one, most relationships end within 7 years. Once the 7 year period has passed, the likelihood of that relationship lasting till death increases significantly. It’s called 7 year ick.