Duly quoted

Do you have ideas in your head that have been there forever, and then when you really need to know, where did it come from, you can't find the source? That's the way I feel about the subject of this post. I searched for the source of one such idea, but found only this:

"Life is an endless series of experiments."

---Mohandas K Gandhi (link)

While this sounds nice, of course it is fundamentally wrong. As one of my early mentors, Bart Sefton, often told me:

"Every good experiment comes with a control."

And the quote I was searching for, which I have always attributed to Milan Kundera, goes like this:

"That's the trouble with life, you never do the control."

I thought it was in The Unbearable Lightness of Being (link), but I can't find it.