Helium is inert in a stronger sense than the other noble gases: no stable compound of it is known under ordinary conditions. Its two electrons fill the first shell completely, and there is nothing whatever for chemistry to take hold of.
Physically it is stranger. Helium boils at minus 268.9 degrees C, about 4.2 degrees above absolute zero, the lowest boiling point of any substance. Below about 2.17 degrees above absolute zero, liquid helium-4 becomes a superfluid: it flows without viscosity, climbs the walls of its container as a thin film and escapes over the rim, and conducts heat so efficiently that it stops boiling and goes glassily still. Pyotr Kapitsa and, independently, John Allen and Don Misener reported the effect in 1938.
Alone among the elements, helium does not freeze at ordinary pressure however cold it is made. Its atoms are so light and their mutual attraction so weak that quantum zero-point motion keeps them mobile down to absolute zero; roughly twenty-five atmospheres are needed to force a solid. This is not a curiosity at the margin of physics but the clearest visible case of quantum mechanics governing a bulk quantity of matter that could be poured from a jug.
The practical consequences are large. Liquid helium cools the superconducting magnets of MRI scanners and particle accelerators, and there is no substitute for it. Breathing a helium and oxygen mixture avoids nitrogen narcosis in deep diving. The high voice comes from sound travelling nearly three times faster in helium than in air, which shifts the resonances of the vocal tract without altering the pitch at which the vocal cords vibrate.
Nothing traditional attaches to helium, and nothing could: it was unknown until 1868 and had never been held in the hand until 1895.