Why have I got You

Why have I got You Picked A Fine Time To Leave Me Lucille going round and round my head? I don’t even know anyone called Lucille. Actually, that’s not true, I do know some of that name – she is the wife of an old school friend. But she isn’t likely to leave me, as I haven’t seen or spoken to her for at least three years.
And I haven’t actually heard that song in ages. Clearly some sort of mental deficiency on my part.