Maybe you thought something was a red flag in a partner, but it really wasn't. Maybe you made the opposite mistake. Maybe it was about a boss. Maybe you thought Python would never catch on.
Share what you've been wrong about, and why/how you realized you were wrong.
I was wrong.
The real value is in solving a problem, and that includes the whole problem, not just the part amenable to software.
I learned I was wrong when I joined a startup that was delivering real estate data to phones (this was pre-iphone, so quite a mess in terms of writing code). I wrote some j2me, and we actually had a product that allowed someone to search from the phone for home information.
While we had the tech, we didn't have (oh so many things):
* distribution
* a business model
* full time effort from any of the founders
Of course if you want to run a business then all of those things are more important than knowing how to code, but for a developer they are not. Instead you should look for a place where those issues are already solved so that your work gets put to good use.
He turned out to be one of the best devops people we had. Just a wizard with infra stuff. He definitely didn't integrate into the culture, but it didn't really matter.
In my defense, it was early in my career and early in the SV years so I thought cultural fit should matter a lot because that's what I was experiencing. It was an eye opening experience to say the least though.
Obviously I was very wrong.
I didn't predict that:
1) people would instantly recognize it as a camera that might be recording at any time and be infuriated by that
2) Google would prove itself to be so shockingly bad at product development and marketing
In the early 2000s, there was a widespread debate about the browser replacing desktop applications - the term Rich Internet Applications (RIAs) was coined. Could browser applications take on desktop software in features and usability? Well, I was sceptical.
Fast forward today and how wrong I was.
Today, 'cloud' apps running in the browser dominate a whole class of business tasks. I used to believe some types of apps like design and graphics apps would never work in the browser unless extremly limited. But even design and graphics apps have found success in the browser e.g. Figma.
The trend of more and more apps moving to the browser (via the cloud) shows no sign of slowing down, only accerelating.
(Whether browser-based apps are a good thing or not is a different question though.)
Yet at the same time I was wrong about not leaving the door open in my conclusions about a person, once I make up my mind about him.
I thought it was ok to be a bully. And being good at it was even better. Not without reason. I worked at jobs where it was a soft requirement.
I thought it was worth keeping up with technical change. Now I value stable tools.
The transformation of our lives and growth of technology that's happened over the subsequent 25 years is something I never could have imagined, it's truly revolutionary.
I also heard Warren Buffet say something rather significant - this revolution catapulted the US to a position of dominance in the world to such a degree, at times it's hard to think of who #2 even was in the information age.
I thought that bitcoin would crash about the time of the pizza purchase story.
I thought more than ten years ago that GNU/Linux would make it on desktop in the next 10 years.
I thought that single life was better for me than having a loving partner and kids.
I thought there was ZERO money to be made as a programmer, so I studied EE instead, in 1981!
I saw almost full month of every day profit even when market was most volatile.