Impedance Mismatch ???

I have to say I`ve never ever even considered trying to make sure various components are matched impedance wise.
But I came upon a thread where it was said that the output impedance of the Preamp should be 10 times less than the input impedance of the Amp.
So out of curiosity I look up what my Preamp and Amp has for those numbers.
The Preamp shows 100 ohms output and the Amp input shows 33K.
What am I supposed to be hearing if there is something awry ??
I`ve been listening for a few years to this combo and I like what I hear,BUT, am I unknowingly compromising the sound or performance somehow ?