Help me understand John Coltrane .... seriously.

Erik, I have trouble with free-form jazz too. I just can’t quite get most of it. I’m more an Oscar Peterson kind of guy. That being said, I will play Coltrane, Davis, et al, in the car, or as background music. This allows my brain to absorb this music without focused concentration. After a few long sessions, I’m ready for more serious listening. After this, if I still don’t get it, I probably never will.

Erik, 

I love jazz and I don’t love Coltrane. I respect him and like some of his work. Overall, I find his lead lines stabbing, terse and not very melodic. He often sounds like he’s racing through scales and modes. I’m with you. 
When I was first exploring jazz 25 years ago I listened to him because he’s in the cannon of popular jazz. Today, I’m down to owning just two of his albums and I rarely play them. 

I recommend picking up a copy of Ted Gioia's book, "How to Listen to Jazz." I've been a jazz fan for decades, but I still found this book helpful and enlightening.

It's not dense, very readable. As you can tell from the title, it's written for the everyman and it not technical.

https://www.amazon.com/How-Listen-Jazz-Ted-Gioia/dp/0465093493/

Hey I don't get Rap "music", it doesn't bother me in the least.  If you do not like bop or post bop jazz, so what?   It does not make any sense to some people. Others can recognize the structure in the improvising.  They play the notes in the chords around the melody. It is like algebra instead of arithmetic.  Oh they know ALL the rules, and know how to break them. It is not totally random the notes they play. 

Help me understand ART .... seriously.

That is what you are really asking because real jazz is art. And as with any art form it is ok if you don't get all of it or appreciate all of it, as long as you try. Just move on to another artist and come back to it latter. The more you listen to jazz the more you will find yourself gong back and appreciating pieces you previously passed on.

But of all the jazz artists, I'd have to admit that JC is one of the more difficult to "get" and best left for serious listening after one has a better understanding of jazz.