If I may crash...
When I was little, I had it drummed into my head that certain foods were "finger food" and certain foods were "fork food". I can only think of a few things that my parents deemed "finger food" (leaving aside things like hors d'oeuvres): corn on the cob, hamburgers and hot dogs, sandwiches, fries, pizza... actually I think that was it. My parents required me to observe proper table manners even when it was just the three of us at home, so I was not allowed (for example) to pick up a chicken leg and gnaw on the bone to get the last scraps of meat. Which, I guess, was a good thing - it meant I learned one set of rules, as opposed to "rules for home" and "rules for company/restaurant".
These days, I'm a little more lax at home - for example, I will pick up the chicken leg and gnaw on the bone. And there are a few situations where you just have to use your hands - for example, when you're eating lobster or ribs, you just have to dive right in and not mind the mess. But for the most part I stick to knife and fork.