Oh-oh! My two cents again.
Sometimes John and Paul created a song title and wrote a song around it, i.e., "Eight Days A Week". It is possible that Paul started with the concept of the album, "Get Back", and wrote a song to include the title, whether it had anything to do with getting back to basics or not.
When Eric Carmen left the Raspberries, his first solo single and album were titled, "All By Myself". Clever. The song was about being alone, but it fit the idea of his going solo very well.
As for John, every reaction by Paul and George regarding Yoko triggered paranoia. Remember his rant about his "beast friends"? According to John, George was even nastier to and about Yoko.