Company lifespans these days are a lot shorter than human lifespans. 25-40 years seems typical, making a company-year 2-3x a human year.

By that yardstick, Google was in its young adolescence when it IPO'd (seems reasonable), was an idealistic young adult when I joined in 2009 (also reasonable), is now hitting a midlife crisis, and will die sometime around 2040.

Yep I'm down with your timeline. I joined in 2012 and it felt like a person in their late 20s or 30s in an energetic but responsible part of their career, just settling down to have kids... But before all the buying of sailboats and sports cars and treatments for baldness...

So IBM is like a 300ish year old vampire then? They really seem like an outlier longevity-wise.

If IBM is a "300ish year old vampire", Nintendo is basically God.

A better comparison is likely an old tree that is mostly dead tissue, but that dead tissue is solid enough to support its own weight.

Certainly it feels like that :D

Well, unlike people, companies don't begin to die at a super-exponential rate once they hit a certain age.

Ignoring the lifespan, they are pretty stodgy and conservative now, so middle-aged just seems a better fit.