Your grandmother’s husband was absolutely correct.
Learning the romance languages is made so much easier with Latin as a basis.
My mistake was taking Latin II, which was largely translating Caesar’s description of Gaul being “divided into three parts.” Yikes, that was a little boring. But then the Italian being spoken in my home became easier to understand.
Likewise "Arma Virumque cano" which is the opening line of Virgil's Aeneid (Latin IV). I am sure that there are also memorable lines from various works of Cicero (Latin III) although his syntax is quite complicated. Of course, the translator's friend is a Latin to English dictionary. The traditional Catholic's friend is the St. Joseph's Daily Missal.
May God bless you and yours!