For detailed journaling, it makes sense to set a regular reminder - say in the early evening - to detail your day's experiences.
Changes lets you do this.
But it's also a mood tracker.
And our brains are surprisingly bad at remembering the details of how we felt earlier on.
Once an anxiety is resolved, it can seem a little silly in hindsight.
So it would be easy to miss a lot of important insights if we only tracked our mood at the same time each day.
Changes sends you reminders at random moments. That way we can track our true emotions, unfettered by any interim passage of time.
It's just more scientific this way.
Our data will be spread out across a wider variety of personal experiences.
If you're interrupted in the midst of a panic and asked to tune in to how you're feeling, the panic can be diffused in the process.
Changes works as a "mindfulness prompt" in this regard.
Here's Dan Gilbert's 2004 TED talk which set me on the path to building Changes and its predecessors.