Few today remember the frustration of typewriters, where speed was a goal, but the faster you went the more mistakes you made. Correcting a mistake in 1945 was a painful process, involving some "whiteout," or other messy, time consuming process. So each mistake produced a wince, and not until the error correcting ribbon came along and acknowledged the reality of typing mistakes did things improve much. Of course being caught with a bottle of whiteout in a typing class was bad for your grade. The introduction of the IBM ball typewriter in the early 1960s at least prevented a tangle of letter hammers from resulting when you attempted to go fast.

But after a month or so most people could type passably well, and slug it out on a cranky home machine when necessary. Most people's typing skills now serve them well on their PCs, where mistakes are but a minor nuisance.