It started with one automation. Turn the hall light on at sunset, off at bedtime. That is the whole brief. I had a spare Pi, I flashed Home Assistant OS onto it, and forty minutes later the light worked. Job done. Or so I told myself.
Two weeks later I have a Zigbee dongle, a dozen sensors, a dashboard I redesign every other night, and a YAML file that has opinions about whether anyone is home. The light still turns on at sunset. It also now turns off if the room is empty for ten minutes, dims after eleven, and sulks if the energy price is high, because of course I wired in the electricity tariff feed as well.
None of this is necessary. That is rather the point of a homelab. But I should warn anyone eyeing it up: Home Assistant is not an app you install, it is a hobby you adopt. The moment the first automation fires exactly as intended, your brain starts listing the next forty things it could do, and your evenings are spoken for. Worth it. Mostly.