"I didn't know that" vs "I don't know that"

[Molly]

[Yankee]

.
Yes, Nessie, the reason I used didn't in my question was that I was referring to the past.

I'm just a little puzzled about Alan's reference to "quibbling" about "all these subtle meanings" of I don't know that and I didn't know that.
.

[Yankee]

[MrPedantic]

For me, the differences would be:

1. "This painting is by Titian." "I didn't know that."

= for me, that is new information.

2. "This painting is by Titian." "Well, so you say; but I don't know that."

= I can't be certain that you have told me the truth.

3. "This painting is by Titian." "I don't know about that."

= I suspect that you're wrong.

MrP

[Nessie]

Thanks a lot, Amy and MrP
This knowledge is very interesting
_________________
... something we never have again, I know... I guess I really really know..

Sorry seems to be the hardest word...