Help me understand John Coltrane .... seriously.

Suppose one were to suggest that Coltrane, like all the jazz greats, is not only playing the song, but is also playing with the song at the same time. I'd suggest listening to "Summertime" as a great example. At points, it's "Summertime," the tune you know, but at others, it's Coltrane doing his thing with it. Until it's "Summertime" again.
I'd suggest not thinking too much, but just grooving as the man makes his way.
-- Howard

Yes those are more accessible Coltrane albums as is even Giant Steps and Blue Train but these alone are limited as a tool to "get" John Coltrane.

A good package for that is the "Live at the Village Vanguard" set where you get multiple and varied takes on the same classic Coltrane tunes on different nights to soak in and process.

Ole Coltrane is an interesting record too. The title track is hypnotic, or at least distinctive. 

Oh hey! The 'Stockholm Concert' from '61 ish'

You don't get the song "My Favorite Things"?

Yes those are more accessible Coltrane albums as is even Giant Steps and Blue Train but these alone are limited as a tool to "get" John Coltrane.

Limited yes, but his more accessible albums are a good starting point simply because you begin to understand his talent, his genius. Others albums, as you've mentioned, include "Love Supreme", Blue Train", and "Giant Steps". 

IMO a lot of folks just getting into Jazz stumble when listening to the more free-form variety. Melody is key for many.