In my opinion, the "healthiness test" for your brain is simple.
"Are you enjoying the uncertainties that you encounter in life?"
If the answer is "yes", then your brain is in a healthy state. If you are able to welcome every opportunity in which you meet new challenges, experience the unexpected, and learn things, then the state of your brain is satisfactory.
If the answer is "no", then you need to reconsider the status quo. If you are unable to meet new challenges, and tend to avoid circumstances where you are likely to encounter the unexpected, then your brain is missing opportunities for learning and growth.
In this respect, the recent tendency among Japanese to avoid the unexpected and follow the trodden road is worrisome.
Why don't you jump into the great ocean of uncertainties? It might be frightening at start, but you will get used to swimming soon enough.