Whereas Einstein's General Relativity was the work of a singular genius, the theory of Quantum physics (aka, quantum mechanics, or just plain quantum) was the work of numerous, great minds. In its essence, quantum is counter-intuitive at best, and down-right mind boggling at worst! The reason is that our intuition is entirely built upon the things we experience, and the truth is we experience very few phenomena on the quantum level.
So although some of the ideas here and in the links below may seem strange, understand that this is because we are simply not used to the ideas since we don't experience them first-hand. But the veracity of a theory is determined by how well it holds up against experimental evidence, not how well it holds up against our opinions, and the principles of quantum theory have been investigated and experimentally confirmed many times since the beginnings in the early 20th century.
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