but I have to keep training my mind in order to secure this like a foundation to my mental health.
I think that this is something that people need to consider. Pretty much everything in our life we are going to lose over time, but as long as we have some thought function, we are able to improve it (even slightly) for the duration of our life. Even as we degrade with age, we can still improve based on the conditions we have.
Definitely, and it takes a lot of discipline to be able to reach our own personal peaks. It's quite difficult to maintain a high level of discipline over a long period of time, but as with everything else, takes practice.