Most symptoms of the "milder" mental disorders (depression, anxiety, adhd, etc.) are things that everyone experiences at some point in their lives.
It's the degree of experience, frequency, and impact that differentiate the two. Also, when those symptoms don't have an environmental/situational/logical cause.
For example, being too anxious to go out with friends, or compulsively checking that the stove is off even though you know damn well it hasn't been turned on in a month. Also, being sad because your pet died isn't a mental disorder like clinical depression.
The line between the two is definitely fuzzy, but psychology is a super complex topic.
I've been realizing lately that it might be from ADHD - along with many other symptoms. Hoping to get diagnosed next year, and hopefully I won't waste quite so much time just quietly stressing out.
If I could freeze time, I would honestly use it to just have as much time to do nothing as I wanted without missing out on real time events. I wouldn't even use it for anything else