According to disc 2 of the 2003 release Let It Be... Naked
, "One After 909" is about a lady who tells her boyfriend she is leaving on the train that leaves after train number 909. He begs her not to go, but she does anyway. He packs his bags and rushes after her and discovers that she is not on "the one after 909," so he goes home depressed and goes into the wrong house.
Loretta - Liverpool, England