In my case, it did help, specially when I started studying other languages.
I’ve mentioned before how my biggest gripe with “modern” foreign-language-teaching methods is that they assume the students have no knowledge of grammar. I’m familiar to a greater or lesser degree with the grammar of Spanish, English, Latin, Catalan, French and German; in one of my German as Second Language classes, that was the minimum amount of languages any given student was familiar with, so we’d analyze the repetitive grammar exercises and say things like “ok, so you use the Akkusativ for the DO, the Dativ for the OO and one or the other for other complements depending on the preposition?” - neither the courses nor the teachers were prepared to deal with people like that. We needed to widen our vocabulary, the exercises were all grammar drills… but once you understand the grammar, there is no need to drill it! The teachers said “German grammar is very difficult,” we’d say “are you kidding? It’s a lot simpler than Latin!”