Though Newton's 3^rd Law states that for every action, an equal and opposite reaction occurs, I see a potential problem with that.

People often use the example of a person pushing against a wall with all his might,

proposing that although the wall is an inanimate object, it (somehow) decides to push back each time the dope above pushes (like a person who doesn't insult anyone but always returns them).

I ask you though - if you stand against the wall & don't push, why doesn't the wall push you then ? Something seems wrong here.

The way I see it, actually, is that the wall is attached to a building, which is attached to the Earth :

Thus the poor dude is trying to move the entire Earth ! And not very successfully. Actually, he is probably compressing the wall a little.

If you still think the wall is responsible, let's change the above situation. Here, rather than trying to move the Earth he's standing on, the dude is only trying to move a small wooden board below him :

Though not nearly as difficult, he can't do this either, so he still feels the wall must be pushing against him.

But I think I can help !

I'm gonna attach a large weight on top of the wall but on the other side which almost balances his weight & that of the bottom board. Now let's see what happens when he pushes against it :