I'm sure, along with Eric's, there a slew of "meanings" to this song; some spot on, matching his....true meaning, to stuff so far out they would confuse the "Plutonian's"! And, then,
the meaning is just the song. Nothing mystical, nothing deep & spiritual, nothing about reincarnation, drugs etc. Like sometimes a good cigar is just a good cigar, Mainline, Florida is just a good song. (Instead of Mainline interpreting to Mainlining, think I-75 & I-95.... Mainline Hwys. in Florida.