Honestly, if I need a vacation after 6 months, I don't think I'm cut out for this work/this company.

Is six months a short time? Maybe it's because I'm European but six months sounds like a really long time to go without even a short vacation.

Haven't taken a vacation in about three years. It hasn't occurred to me to do so! Love my job so much.

It depends. I got caught in crunch time at my current company and needed a vacation bad after 3 months. It ended up coming a little later, but I got copious vacation in order to get back to normal (~3 weeks).