In the past, our memory did not need to be long. We only needed to think back to the past few years to make decisions about what we were going to plant, where our tribe was going to move, etc. Now that short memory is a problem. We don’t notice when things move incrementally, we see something move, and if it stays there for awhile, we reset our baseline to that new level and forget that it was ever at a different level. Sure, we can look back and note that it was once at a different level, but we can’t wrap our minds around the idea that it could ever go back to that level.
I’d say that where the readers of this site differ from the “common” in common sense is that we don’t use common sense to make our decisions related to housing. If we used the common sense, we’d be buying up houses so we didn’t get locked out of the market.
We are using logic and not common sense (just because a bunch of people believe something doesn’t mean it’s true) to override our instinct of thinking that the new baseline of housing prices is set at about $500,000.

i wish i bought a home for 200-250k. problem is that it was overvalued. then it is more overvalued now.

Common sense really refers to herd mentality. Usually it’s correct like don’t jump in the water when there are sharks swimming around, or don’t eat the mushrooms you see growing on your lawn, that’s all common sense. But common sense isn’t always correct. Common sense in the late 90s was that you bought dot.com stocks, but look where that ended up. Like I stated above, common sense says that you don’t eat mushrooms growing on your lawn, but if you are a mycologist then you have specialized knowledge and can decide whether the mushrooms on your lawn are edible or not, even though common sense says not to eat the mushrooms.
The people on this board are not using common sense. It sounds bad, but it’s not. They are questioning the common sense and building their own specialized knowledge about the subject and making their decisions based on that, not common sense.
Sorry to get all English teacher on the term, and maybe I’m interpreting it incorrectly, but I believe that’s what common sense is.

I disagree. Common sense isn’t the herd think, in fact, it’s quite the opposite.

Common sense is applying some pretty basic thought and understanding to something. i.e.
Spending $2000/month when you make $1000/month will lead to problems.

Sleeping with my wife’s sister could be problematic.

Smoking 3 packs a day won’t be good for me.

Having a house payment of $2200/month when your take home is $2400/month is going to get rough.

I don’t know what I’m doing, I’ll ask someone I trust that does… that’s common sense.