Was it a burning desire to fix the things that broke during your childhood? (Pinball machines, gaming consoles, music players...)? Did someone inspire you or encourage you to get involved with test? Or, was your 'vocation' discovered by another entity, such as the armed forces? For me, it was the fascination of being able to see things that cannot be seen without instruments. Kind of like being a medical doctor, but without all the unpredictable contagion!