My digital brain started as a way to stop outsourcing my memory.
I have ADHD and autism, along with depression, anxiety, and sleep issues. My brain drops pieces. I lose track of time, birthdays, things I agreed to do, the last time I took medication, when I need a refill, what is actually urgent, and sometimes the thread of a task itself.
For a while, some of the answer was other people. I asked friends and family to remind me. My wife gave me a short list of chores every day. It helped, but it also quietly made someone else responsible for keeping me on track. Everyone is busy. Everyone needs help. When you need that help consistently, it can start to feel like you are making your problems someone else's job.
So I built myself a digital brain: a system that can remember dates, surface the next thing, hold context, and give me a little reward for doing the boring stuff. It does not make my brain different. It gives my brain somewhere to put the pieces.