Unlike late teens or early 20's, from the age of 23 onwards is considered "old" for someone who still has screen time limits imposed by their parents and is deemed too immature to watch movies like Deadpool. This term highlights the generational gap in perceptions of age and maturity.
At 23, I feel old when my parents still impose screen time limits and think Deadpool is too inappropriate for me, making me question if I'll ever really grow up in their eyes.
When you link someone to a website they have already seen. It refers to a fictional top-level domain (like .com, .net and .edu) that, if it existed, would house all the old shit everyone has seen but you.
Example 1
Guy1: Have you see tubgirl?
Guy2: you meanwww.tubgirl.old?
Example 2 - The lazy approach
Guy1: Hey, check out todays woot
Guy2: .old