It never happened to me because I knew from the beginning that it was Simple Minds, but if I hadn’t, I think I would have assumed it was a U2 song. “Don’t You Forget About Me” really sounds like a pastiche of everything U2 did up until about 1985.
So, I don’t ever really get any of these songs wrong, but does this guy, Keith Hampshire, sound just like Neil Diamond to anyone else?
I didn’t realize he was a British artist, very popular in Canada in the day, but never really cracked the international market.
It’s a corny song and so therefore fits in perfectly with Neil Diamond of the day. Am I the only one?
ETA: I actually heard this on the radio today!
Not the music, but as for his voice, he really sounds like Neil Diamond when singing in the lower register.
I also thought “Hot Child in the City” and “Roxy Roller” were sung by a woman until just a few weeks ago!
For a while I thought Break my Stride was sung by a woman.
I keep reading the title as Songs you’ve masturbated to.
Can’t think of any, but… Ew!
Relax.
When you want to suck to it. When you want to come.
Nothing sexual there!
I was making a joke. Not a great one, but still.
“Stairway” has a good buildup and climax, if you can hold back for 7:55. 
As soon as I saw the thread title, I thought of Long Cool Woman in a Black Dress. Then I clicked, and there it was in the OP.
Ha, this was going to be mine. I thought it was by David Bowie until I saw it attributed to Iggy Pop online years ago. The singer did sound kind of like Iggy Pop on his mellower songs, but the lyrics seemed a little too clean for Iggy. This was pre-Wikipedia and pre-YouTube, so it took quite a bit of searching to find the actual artist. I felt kind of bad for Edwyn Collins, because I’d heard the song plenty of times without ever hearing (or at least remembering) his name.
Same here, until about a minute ago!
Really? I can’t say that I see (err “hear”) that.
FWIW if you create a Pandora station off the song On the Dark Side, besides Bruce it’ll play a lot of same-era Bob Seger. Which I can totally understand. Not that you’d necessarily misattribute the song to the OP’s point, but they’re stylistically quite similar.
I didn’t really know Bruce’s or Mark’s voice that well when I was a teenager and first heard Walk of Life, but the music itself seemed Springsteen-ish. Plus Born in the USA had been really big and I’m not sure I had ever heard of Dire Straits.
Oh, I thought of another song I thought was Fleetwood Mac, Red Rider - Lunatic Fringe. The music more than the vocals reminds me of Fleetwood Mac.
Not a song, but sometimes when I turn the radio to NPR I’ll think I’m listening to Terry Gross, only to find out that it’s Robin Young.
I thought that was Bryan Adams for quite some time. Later, I found out that I was blaming the man unfairly.
I thought Lunatic Fringe was Golden Earring.
*She Drives Me Crazy *was surely by the Bee Gees.
The Fine Young Cannibals song? Really? Their singer sounded like nobody else and sang in a much deeper register than the typical falsetto Bee Gees. 
Andy Kim claimed in Billboard that on his early hits, the tapes were sped up to make his voice sound higher. (Source: The Billboard Book of Number One Hits)
Anyway, my contribution to the thread: When I first heard it, I thought Eric Hutchinson’s “Rock and Roll” was a Jason Mraz song.
I thought “Hold Me” by Fleetwood Mac was an ABBA song.