This is what I'm talking about when I say "obtuse". No, we don't know for certain that Ned didn't share those two things with Catelyn, since Martin didn't provide us with an exhaustive list of subjects the two had discussed. But he spent a significant amount of time describing (1) how intensely private Ned was; and (2) how reluctant he was to discuss the events surrounding Jon's parentage. So it's a reasonable inference.
Lyanna's final words-- "Promise me, Ned."-- haunted her older brother for the rest of his life. We don't know what that promise was, but if it was indeed to take care of Jon and to tell no one of his true lineage, can you still honestly say it would be "strange" for Ned (knowing what we do of his nature) to stubbornly keep that promise, even from Catelyn? I don't.
No one has argued that your position is irrational or impossible. I just think you're doing a pretty poor job of putting yourself in Ned's shoes. The man risked (and lost) far more than this promise cost him later on.
I'm obtuse for stating a point you continue to pound over and over may not have in fact even have happened??? wow
On the point of obtuse, how many times do I have to type it??? Telling Cat who Jon’s parents actually are isn’t my point with Cat!
As far as your points-- I don’t see Tourney at Harrenhal being some major event in Ned’s life... and don’t see why he would have anything to hide there anyway… because of the flowers at the end??? Sorry, I honestly don’t see how anything attaches to Ned being private there.
I also don’t see this ‘affair’… I know of rumors being mentioned in the books… If my wife brought up a name of a women I was unjustly liked to in an affair I would react as Ned did… I don’t know if that’s being ‘private.’
On the flip side he did tell Bran about his owing his life to Reed… and told him the name of the man who almost killed him... that seems like a pretty private thing to just share with someone, no?
He has held the truth of Jon's mother, he know that much for certain.
All in all I don’t see a ‘significant amount of time’ being spent establishing his privacy… at least where his family is concerned...
As I have said before I like the theory, it’s exciting and well put together, but I still see no rational reason to let this hatred of Jon linger… unless he’s really a bastard.