Are we expecting too much from causality?

I remember my professor saying that Hume couldn't know for sure if his eggs for breakfast would nourish him or kill him.

I'm wholly on board with the idea that for any causal relationship between x and y, if we were only familiar with x we could never infer y as an effect from x. If I understand Hume correctly, his argument was that we project onto the world our perception of cause and effect. I agree that there is so much background information that informs our understanding of cause and effect. I didn't know why mom said "Don't touch the oven burner!" until I experienced the effect of being burned by it. There was nothing in my background, nor in the perception of the red hot burner, to clue me in on the effect of pain.

But, to be clear, I believe cause and effect are real features of the world. They are metaphysical realities and not mere projections of our minds onto the world. Nonetheless, we discover causes and their effects. We can't infer a particular effect from its cause.

What I wonder is, are we are looking too closely at the relationship between cause and effect when we try to find some third thing besides the cause and effect? In other words, are we expecting too much when we try to find that which connects the cause and effect?

It is this mysterious third thing that seems to be the cause of all the metaphysical and epistemological trouble. Imagine I tell my friend that Betty Jo and I are in a relationship, and then my friend begins to look around us hoping to find this third thing, i.e. our relationship. But, there is no third thing. We are the relationship. When we talk about causal relationships, we're not talking about three things: the cause, the effect, and the connection between the two. Maybe our metaphysical expectations are too high given the epistemic disappointment of not being able to infer the effect from the cause?