Of derailing thoughts

I suffer from a terrible curse.

Sometimes my thoughts vanish, completely, mid-thinking.
It usually happens when I am thinking about something and then I, usually unconsciously, try to give it this different look, like looking at it from outside. And then I realize I'm thinking, or something.

And from that moment on, everything happens instantly. Everything crumbles down. I only have time to grab a few pale elements of the derailing thought. I seriously forget everything I was thinking. And then I keep still, holding on to the elements left so they don't leave me too, all while trying to recover the core of my lost thought.

As my mind is busy trying to keep the clues from escaping, I find it hard to search around. Sometimes I let the clues go (and they disappear instantly as well) as an attempt to focus on remembering the lost thought. I've always failed. I have this frustrating feeling like when you die in a game and you have to restart from the previous save point, some twenty-minutes ago.
But I remember once succeeding at recovering a derailed thought. I have to keep in mind how I've done that. I think I've tried to give the piece a different point of view, like, literally.

Anyway, that things terrifies me. I hate to think of it happening during some important speech or something.