I learned early smoke is what makes electronics work. Some how they stuff smoke into these little black chips and if the smoke gets out the chip will no longer work.
But it's not only smoke they cram in. Fluff too. Ca. 1970 my bedroom was filled with stinky fluff when an electrolytic capacitor went into a circuit backwards.
Tantalums became more violent later in the decade -- I remember seeing power-supply burn-in fixtures marred by the explosions of tantalum caps inserted backwards. One of the company founders narrowly escaped injury when one chunk of cap clipped his nose bridge (and he was Asian).