mutations occur all the time; pretty much at the moment of meiosis; they become relevant at conception. Homo sapiens taking ~200,000 years to invent an ipod, after taking ~300,000 years to become a unique subspecies, after taking ~2,000,000 years to speciate under the genus homo doesn't seem like something that happened "overnight" at all.
besides, what you're referring to isn't biological evolution, but scientific/technological progress; which isn't something that develops linearly. Once one human makes a discover known to other humans, multiple humans are able to build from that discovery and make their own discoveries, spreading out at an exponential rate.
it's not like someone has to reinvent maxwell's equations every time they want to do something involving electricity.