Found a weird sign

On my way to loot a cave, I found a little hole where there was only a skull and a sign with a sentence, but the words aren't... complete
Anyone can tell me what is this about ? And maybe what's the sentence ? It's quite hard to understand

 

probably the last words of the skull thats faded away. i can only recognize remember, fools/ feels (?), and please (?) tho

 

There are lots of little hidden things like this scattered around the map they mostly just give a little more depth / lore on what has happened in the area although sometimes you might find an easter egg

 

The sign says:
Remember our lesson fools who inherit this place...