What is the hardest fruit to juice?

Have you ever found yourself pondering over the challenge of juicing various fruits, wondering which one poses the greatest obstacle? Well, I'm curious to know, what is the hardest fruit to juice? Is it the dense and fibrous texture of a pineapple that makes it difficult to extract its sweet juice, or perhaps the small and hard seeds of a pomegranate that create a hassle during the juicing process? Could it be the thick skin of a mango that demands extra effort to peel and prepare for juicing? I'm intrigued to learn about the fruit that leaves even the most skilled juicer scratching their head, trying to find the most effective way to harness its deliciousness in liquid form.