It could be a listing mistake, a fixer upper or someone needed to sell quick for financial issues or big life change situation. 

All the experienced investors I've listened to have said that at some point you will fail, make a mistake, and/or experience hardship.

You'll make some mistakes starting out, and you'll learn from them, and you'll grow.

My agent made a mistake.

She has a folder of organized information of the banks mistakes.

That was a mistake.

I'm beginning to wonder if I didn't think this through properly and am now learning one of those "very expensive" mistakes. 

I made my first big investing mistake within minutes after the purchase.

I am moving slooooowwwwwly at the start, because typically when things get rolling for me, they roll very fast, and I need to have a good foundation before committing (and of course making the requisite newbie mistakes). 

Don't go into it blind, learn from others mistakes before making your own.