Knowing and knowing

I am fascinated by the phenomenon of knowing something intellectually and still escaping the application of that knowledge to oneself. Perhaps it could be described as the difference between knowing theoretically and actually taking something to heart.
Years (too many) ago when I was still a struggling actor in New York City, I formed the hypothesis that those grand celebrities who take their own lives (Karen Carpenter, Robert Young, Brian Keith, and those who essentially committed suicide like Montgomery Clift, Marilyn Monroe, et. al.) often do so for the following reason: there is an emptiness that they believe can be filled by fame, by the adoration of millions. And when it doesn't, they're bereft of all hope.
The bitter irony is that that mindset describes me. Astonishing to me that I could have that theory so clear in my mind and yet entirely miss applying it to myself.
Thankfully now there are SSRIs that take the edge off the depression and anxiety. Without them, I must confess, I know where I'd be. And there is a group here on goodreads called "Bloggers Beating Depression". I so appreciate them. I'll have to post this to that group.
It took the death of my sister and the loss of our ancestral home built by my maternal grandmother in 1915. (For those of you on the other side of the pond, that's a legacy here in the US).
I had no idea that house meant anything to me. How I could fool myself so completely strikes me as the height of absudity.
I suppose self-delusion is not all that uncommon. At least, I hope it's not just me!