Should one think of it as misremembering or merely reremembering? I think sometimes we rearrange our memories in a more aesthetically pleasing way. For instance, I went for many years believing that I saw Led Zepplin opening for the Who in 1969. Not too far off. I did see both bands at the Edmonton Gardens - the Who in 68 and Led Zepplin in 69. I prefer my original memory, where Zep was an enormous revelation. As far as I was concerned, I had never heard of them before and discovered them at the Who concert. Best discovery ever...or at least it would have been if it had really happened. But alas, there were two separate concerts. I missed the Who as a backup band in 67 (I was too young to go to concerts alone. And I don't have any memory of who opened for them when I actually did see them in 68.) So my memory of The Who and Zepplin together was much more efficient and pleasing than the truth. Truth is highly overrated. After all, that lineup did actually play in Maryland 3 months later. So I think I'll keep that memory.
Did I ever tell you about the time I saw Led Zepplin as opening act for the Who? Man, that was a concert!