[dataflow]

Oh I didn't mean to say it was impolite. I just meant the logic in his reasoning isn't really sound. If it was only intended in jest then it's a great conversation maker, but I thought it was worth pointing out the issue with the logic given that the ultimate goal was to apply similar logic to the OP's question.

[nefitty]

Ah yeah, I get that. I guess the optician's comment just struck me as deep in an abstract sense. It's like he pointed at some truism about specialization in contemporary society. That's completely counter to the extremely-online punk/hacker DIY ethos that resonates with me, so the effect was like getting my spine realigned.