Here are the ones I'm most tired of hearing.
All in Doing Deals
1 in 5 deals is getting down valued right now. Most of them didn't have to be.
I've done a fair bit over the years — student, BTR, co-living, commercial — and most down valuations I see were avoidable. 
I once talked a widow out of selling me a great deal
Turning it down cost me nothing I'd want to keep.
The Deal Order of Operations - the 7 things to sort before you offer
Most people assess a deal in the wrong order. They fall for the asset first and check whether it works second.
The fear that keeps good investors small
You don't grow out of the fear. You just get better at doing it anyway.
My first development started after I looked at the wrong building
I look back at that deal and I see every mistake I didn't know I was making, and I see the one thing I got right, which was refusing to walk away.
