...I don't want to be "told" what to do by anyone or anything which is seemingly out of my control. That being the case, I have decided to get in control of my own "vessel" and make it my choice of who and what I want to be on my terms. Only then can I say I'm truely in control of my own destiny.
I understand that thoroughly. But consider this.

You may train with weights and dramatically increase your strength, but you'll never be able to shift the muscle attachment points on your bones that determine the efficiency of your muscle strength. The variable you can control is huge and it's a worthwhile thing to do, but it is stuck inside biologically determined limits. Not everyone can be the worlds strongest man no matter how hard they try.

Similarly you can exercise your brain and you can grow new neural paths and connections and substantially improve your intelligence, but still only within a certain limit.

We all can make the best of what we've got. There is a huge difference between being unfit or being fit no matter what muscle attachments you were born with. But ultimately you can only push so far with what you are born with.

Interestingly they've found people seem born with a baseline of happiness. Things can shake it around, depression can drop it and there are skills that can be learnt to push the line up. You may only be able to shift it only so far from the baseline you are born with but even that is enough for a melencholy person to gain a lot of joy and pleasure from life.

There are times it can be appropriate to not have full control though. There are some things that you must give in to a little to gain from.. like a 'chinese finger trap'. My disability is like that, fight it, force it and you get worse, work within the limits and you stretch the limits and get (to a reasonable degree) better.