That's because, well, when you buy your first house you might be twenty-five, so thirty years brings you to age fifty-five; that's close enough to retirement.

这是因为,你可能在25岁时买第一套房子,当还清30年的贷款时你已经55岁了,都快退休了

耶鲁公开课 - 金融市场课程节选