Questions & Answers about Je eet hier vroeg, dat is de gewoonte.
Does je in this sentence mean "you" specifically, or people in general?
It means people in general, much like the English general "you" or "one". The second part of the sentence, dat is de gewoonte (that is the custom), is your big clue that this describes a general cultural habit rather than addressing what you specifically are doing.
Could I use the word men instead of je to mean "people in general"?
Yes, you could say Men eet hier vroeg and it would mean exactly the same thing. However, men is quite formal and mostly used in writing or on official signs. In everyday spoken Dutch, people almost always use je.
Is the noun gewoonte related to the word gewoon?
Yes! Gewoon is a very common word meaning "normal" or "ordinary". Adding the suffix -te turns it into the noun gewoonte, which means a "habit" or "custom"—literally, something that is normally done.
What exactly does dat refer to in the second half of the sentence?
Dat (that) refers back to the entire situation described in the first half of the sentence: the act of eating early. It acts as a bridge to explain that this specific behavior is the custom.