Water is the rebel molecule of the chemistry world! While other substances obediently expand when heated and contract when cooled, water's like "nah, I'll do my own thing." It expands when frozen, has maximum density at 4°C, can exist in three states at Earth's surface conditions, and has absurdly high surface tension. Plus it's a universal solvent, has that weird hydrogen bonding thing going on, and requires an inexplicable amount of energy to heat up. Chemistry professors just gesture vaguely and mutter "hydrogen bonds" when asked to explain why water breaks literally every rule in the textbook. It's basically the chemical equivalent of that one student who somehow gets everything wrong yet still arrives at the correct answer.