The social media phrase “I was today years old” is a humorous way of saying it is brand new information for me. It is a playful phrase people use when they get to know something they should’ve known and understood a long time ago.

It is mainly used for things that are considered common knowledge among people but are unknown to one person. It can be something as trivial as learning a new form of the verb.

Example

For example, someone might say, “I was today years old when I realized that I should wear sports shoes for hiking.” Or “I was today years old when I got to know that Meta owns Instagram.”