How Did People Predict Previous Successful Stocks?

Ok so i’m younger and really new to this so please don’t get mad at me if something that i’m saying is wrong. But like those people who invested in Amazon or Apple before they became successful, were they just really lucky or was there like a pattern in them before they became successful. I don’t just mean like whether it went up/down, but was there other evidence at the time such as media or marketing that hinted they would become popular?