Good Saturday! I hope your day goes well and the Good News lives in you! We like to beat ourselves up with the 'should have known' thing. Of course, sometimes that analysis is correct, as in when we are saying it to admit a mistake. Much of the time though, we use it to say we should have been in the knowledge that only God holds, and then we are quite wrong.
You leave a person's house to run an errand. Everything was fine, the elderly male person under your care was watching television, and there was little chance the television set would harm the fellow in any way. The programming on the television is a different case which I am not addressing here in this discussion. However, while you are gone the dude goes and expires on you. The brand-new 83" wide screen television monitor didn't fall on him, he just reached his expiration date at the very moment you were needed elsewhere. What do you say in that case? "I should have known! Oh, it's all my fault. If I had been here..." Do you take the television set home real quick and put his old one on the stand?
You, should have known? Who do you think you are in your omnipotent knowledge? I should have known? Sorry, God didn't consult with me. And, why should God, the essence and embodiment of perfection, consult with us in any case? We tend to blame ourselves for too many should-have-knowns when we had no way to have known. If you steal the former fellow's TV set with the weak rationalization, "He would have wanted me to have it." Then put it on a weak stand and it falls on you and kills you dead. Well, then yes, you should have known that the wages of sin is death because Paul said that in the Bible. For the stuff we don't know let us walk in faith with the One who does know all things. We'll leave the burden of that responsibility with our Lord.
Have a better Saturday in Christ,Bucky