> For example, the conventional wisdom that functions should be less than a page of text and that they should do one thing and as abstracted as possible actually makes it quite hard to understand what a program does when you aren't familiar with it.

It does? Maybe you mean something more extreme when you say "as abstracted as possible" but for /reading code/, I generally find it easier to get the high-level picture and avoid getting bogged down in minute from code that looks like this:

  function sendReport(params) {
    var dataSource = findDataSource(params);
    var data = dataSource.generateData();
    var report = reportBuilder.build(params);
    sendReportEmail(report, param.recipients, this.template);
  }

... versus a flatter one-page implementation with 15 lines of data loading, 20 lines of report, 5 lines of email templating and 15 lines of communicating with the mail server... all sprinkled with variously scoped try..catch blocks. It also helps me focus in on the part of the task I'm really interested in without trying to load the entire system in my head.

For /writing code/, I do agree the reverse is often best: start by doing the simplest thing that works, and then refactor it into something cleaner.