While many posters have cited the continuity of human experience, the value of history in my life is that it highlights the discontinuity. Unfortunately, this requires a bit closer study than most history classes seem to provide.
There is a powerful tendency to characterize familiar customs or practices as “natural” or intuit “obvious” physical or practical advantages. To me, this tendency seems particularly strong in the US (though not uniquely so). It’s so strong that even our history books often contain strong -but provably incorrect- implicit assumptions that things were always, or usually, done in the past, as they are now. The small details of life, business, government, etc are particularly prone to pass unquestioned.
Learning how things were really done, and encompassing the range of actual human beliefs in our own culture, in even the fairly recent past, is truly mind-opening, which has practical value in solving problems, understanding the world, and fighting petty, often unstated, prejudices in ourselves and others.
In recent years, it has been popular to mock the prejudices of the Victorian era, and the way it colored their science and every other aspect of their understanding. I honestly feel that we won’t fare any better in the eyes of future centuries. Even many of the “traditional values” that some of our leaders are trying to turn us back to, were not the actual prevailing views and practices of the “idyllic” 1950s/60s; a study of the details of actual history can keep us from pursuing social policies based on media images of a past that never was, and to see the problems those policies actually caused in the past.
An easy way to get started is to watch PBS’s version of Reality TV, e.g. “1900 house” where a modern family lives the life of a middle to upper middle class London household, using authentic materials, machines, and practices in accord with turn-of-the-century household guides [which were very important to running a household well at the time]. The show does a good job of showing how remarkably different daily life was just a century ago, but if you think as you watch, you’ll see that the differences run even deeper, with broad implications. Other PBS shows of this type, like “colonial House” (name?) are equally instructive. I found the contrast between “Frontier House” and “1900 house” [just 20 years apart in time) to be particularly instructive – not because of the difference between life in 1900 London and 1880 Montana, but because of the similarities! (at least by our standards.
Socrates reportedly said that the unexamined life is not worth living. I tend to agree – but more importantly, those who examine their lives have a better chance of finding better choices and solutions than those who dwell in a herd-like consensus view that is, as often as not, quite mistaken on the facts.