Sometimes people aren't sure what they'll do in retirement. Others have a pretty good idea. I was in the middle: I wasn't sure about my long-term plans, but there were a couple of things I knew I wanted to pursue early on.
We live in Fort Collins, Colorado where there are a lot of freight trains. Significant traffic disruptions occur daily and are a source of frustration for many. Before I retired, an article in the local newspaper highlighted a thought from our city manager lamenting the fact that there was no way for us to check our phones to obtain the status of nearby train traffic the way we're able to check the status of airline flights and the weather. He stated that the city couldn't solve the problem because railroad companies weren't willing to share schedule and location data. We, however, live on the edge of town and have a clear view of the tracks. It's easy for us to see (and often feel) when a train is going by when we look out a window.
The perfect retirement project was handed to me "on a silver platter", or in this case, via a newspaper article: Develop an automated system to notify users when a train is headed toward town. People could use the warning to "get onto the right side of the tracks" before the inevitable disruption occurred.
With lots of guidance from numerous friends who knew way more than I did about automation hardware and software, the train detection technology was developed. And since I hadn't been a software developer for over 35 years, it took quite a while and resulted in periodic bouts of frustration. On the up side, it turned out to be a cheap way to pass a lot of time. (You can read more about the Train Alert development process and web app here.) My wife was even pulled into the effort to help with the user interface and promotion efforts.
This project was started and finished just because we wanted to see if it could be done. However it also took some (pleasantly) unexpected turns:
One of the things I enjoy most about retirement is having the time to pursue things that sound fun or interesting. It's even more fun when those efforts lead to fun you never could have anticipated.