Filaments blow by burning through.
When cold the resistance in the filament is very low so a big current passes when switched on (heating the filament, which increases the resistance, and reduces the ampage being drawn once at a steady state). If there is a particularly narrow point in the filament, this will be the point of greatest heating.
Over time the tungsten sublimates from the filament, and ends up on the inside of the glass causing a gradual narrowing of the filament, and hence failure, usually at the point of greatest current flow, ie when turned on from cold.
When bulbs die early in life I would expect it was a crap bulb: imperfect filament, trace of oxygen in the bulb (or a small leak allowing it in)
LED bulbs usually fail when the circuitry cooks - the LEDs themselves should last decades
Last edited by: Lygonos on Tue 1 Jan 19 at 19:01
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What causes bulbs to blow? 
What causes bulbs to blow? 