I'm not toootally sure on this - whenever I've heard this phrase it's less about people and more about qualities. Things like "his bravery knows no bounds" and "her potential knows no bounds". You're talking about seemingly unlimited potential for those qualities.
I've never heard that specific phrase used for talking about restrictions on behaviour, but there are lots of very similar variations that are. But I'm just pointing out some possible confusion - if people do use it then let me know!
I don't understand why when the universe has no "limites" an alternate translation of "limit" was suggested, rather than the plural form I used. Six sentences later I used the singular "limit" for the children who have no "limites" and it was marked wrong because I should have used thr plural "limits". I am missing a fine point of grammar when the universe can have either no limit or limits but children can have no limits but limit is incorrect for the same word.
You mean when you translate to English? Spanish uses the definite article in places where English doesn't:
Sometimes it's clear what's meant, and then you can just think 'how do we say this in English?' For this sentence, I'd say you could read it either way - "children have no limits" talking about children in general (as a concept, if you like), or "the children have no limits" talking about some specific kids.
So either translation should work fine, because without any other context we can't really tell which one is meant. But for other sentences, where the meaning is clear and the English version uses the definite article, then you do need to use them