It's never been a better time to get into DIY electronics projects. Literally every part of the process is well within a curious hacker's abilities. Microcontrollers and cheap sensors/displays started becoming commonplace around 15 years ago, and the most recent innovations are good and cheap PCB production and 3D printing your own parts/enclosures.

You might check out https://hackaday.com/blog/. They quite often feature projects from people who built the thing they wanted, instead of buying it. (Often because the thing they wanted couldn't be bought in the first place.)