Perishable Knowledge

Some information matters. Most information doesn’t. Learning things that matter makes you smarter. Knowledge that doesn’t matter is called trivia.

There is no absolute reference point for intelligence. Being smart is a competition against your age cohort. Trivia is the junk food of information. If you fill your head with trivia that means you’re not filling your head with useful information.

Knowledge has a shelf life. Useful knowledge becomes trivia by going out-of-date. In theory, there is a spectrum between trivia and enduring wisdom. In practice, the distinction between trivia and enduring wisdom is binary because knowledge is distributed on a log scale. The shelf life of knowledge tends to be either longer than a human lifetime or much shorter than a human lifetime.

History tends to matter because history is curated. Hearing about something that happened 200 years ago is evidence that the the importance of the event has stood the test of time. Facts with a shelf life much shorter than a human lifetime constitute trivia.

How do you determine the shelf life of a fact?

Humans are mortals. The older we get the more likely we are to die (in the next year)[1]. According to Lindy’s Law, immortals (like vampires) become less likely to die (in the next year) the older they get. A country or a language that has been around for a thousand years is more likely to persist for another thousand years than a country or language that was invented yesterday. The life-expectancy of a non-perishable thing is proportional to its age.

I like Linux/​Unix because it so rarely changes. Unix was invented in 1969. It is 52 years old. I started learning Linux nearly ten years ago. Everything I have ever learned about Linux remains useful to this day. My knowledge of Linux grows monotonically. I expect my knowledge of Linux to remain relevant for as long as I can program computers.

I dislike Android/​iOS development because it changes frequently. I first programmed an iPhone in 2015, around the time Apple released the Swift programming language. Swift is a superior programming language to Objective-C for programming most software on a modern iPhone. My older co-workers who learned to program in Objective-C had decades of accumulated knowledge rendered obsolete.

Apple changes their development toolchain so often that half my time was spent keeping my app up-to-date with Apple’s rapidly-changing development environment. My knowledge of Apple software went obsolete as fast as I could learn it. The only durable fact I learned was “don’t write native code for iOS”.

Big companies changing development environments under their programmers feet goes all the way back to when Microsoft dominated the software industry.

The companies that do well are the ones who rely least on big companies and don’t have to spend all their cycles catching up and re-implementing and fixing bugs that crop up only on Windows XP.

Fire and Motion by Joel Spolsky, published in 2002

Want to get off the treadmill of learning a new IDE every decade? Code in Vim (or emacs).

Junk Media

New information tends to have a short shelf life because of Lindy’s Law. Avoiding transient information like news, trends, intellectual fashions and so on makes you smarter. But it’s also important to respond rapidly to major events like COVID-19. How do you respond to events like COVID-19 if you’re ignoring the news?

I was aware of the threat a global pandemic for many years before COVID-19 existed. I started paying attention to COVID-19 when Wuhan was quarantined. I was keeping tabs on COVID-19 for months before it became a major news story in the USA.

Mass media has a record of misleading the public about where things are going. These were not failures of the system. These are examples of a propaganda system functioning as intended.

News Makes You Stupid

The day person-to-person spread of COVID-19 was confirmed in the USA I stocked up on emergency supplies. By that afternoon, I was figuring out how to profit off of it. My company was eight days ahead of the competition. By being first, we got all of the media attention. We were on national television and world news.

News is mostly noise. Only a tiny fraction of it is useful. News outlets are incentivized to tell you everything matters. They never say “nothing of importance happened today” even though nothing important happens 99% of the time. It’s like how Facebook tries to find something to notify you about every day. If it’s not going in the history books then it doesn’t matter.

You can respond intelligently to world events by planning ahead. You should have a list of sudden events you’re watching out for. Here are a few items on mine.

Responding to world events is like playing poker. You should play tight and aggressive. Playing tight means you ignore almost everything. Playing aggressive means you bet hard when you get that suited Ace-King.


  1. ↩︎

    Except for a rapid gain in life expectancy shortly after birth.

  2. ↩︎

    Fukushima doesn’t count unless you live in Japan. We’re overdue for much worse.

  3. ↩︎

    What goes on your list depends on where you live. If you live in England you can ignore the threat of earthquakes.

  4. ↩︎

    Sometimes I respond to things that don’t happen. I thought clubhouse might be a big deal but it wasn’t. I also downloaded 抖音 well before it became popular in the USA under the name TikTok. That one did turn out to matter.