How do you think that could have been done?
General principles. Doing things isn't ever that difficult relative to the psychological capabilities we casually assume ourselves to possess. We then fail to update correctly and include that goals are difficult rather than concluding that over long time horizons we don't work the way we very casually seem to over periods of a few minutes.
A monthly thread for posting rationality-related quotes you've seen recently (or had stored in your quotesfile for ages).