Variations on a September Theme

I have just listened to Rachmaminoff's 18th variation from Rhapsody on a theme of Paganini and I thought its melody sounded awfully similar to Neil Diamond's September Morn. A quick search online and apparently Diamond took inspiration from this piece to write the song (along with a French composer, Gilbert Bécaud).
It is mentioned in this blog post.

I feel proud of myself for having caught that similarity.