I've always had an interest in word origins, so this was a strategy that played on a strength. But doubtless, cognates make things a bit easier for language learners, and knowing how filial languages changed from ancestral roots (like Romance languages/Latin) can help a Spanish speaker wring some meaning from French. As it is, I've got a few Harry Potters in French, and I've made modest headway whenever I leaf through those copies.
