Before you embark on a genuine pursuit of mental growth, make sure you are ready (as much as one can be ready for such a thing) to deal with new suffering that you have not yet encountered.
Seriously. You might think being smart and capable is all that, with achievements and recognition. It does have advantages, and helps protect and heal and strengthen self-esteem. But beyond a certain point...
Beyond a certain point, growing as a mind means entering a personal hell. It is growing too big for the cage that is this life. The cage doesn't loosen. The cage can't loosen. The mental growth that I have experienced has had these fun results:
My thoughts are too "wide", too many angles and associations active at once, to the point that speech linearity is a constant problem.
I have such large chains of inferences and bodies of evidence and knowledge forming my conclusions that now trying to convince or explain my ideas causes me to experience working gridlock most of the time.
My understanding exceeds my thinking limits to the point that I often can't make progress because I'm aware that I'm not able to hold all of my relevant ideas, knowledge, and heuristics at once: like trying to carry too many things in my hands, in the dark. I know I am not holding something important, but reaching for it usually causes another thing to "slip" out of it. The brain gets better and the grasp widens just a little bit if I constantly push, but it's exhausting, but to do anything less is to know I'm wrong.
A lot of the conclusions of my reasoning that I could once readily explain have been wired into automatic and often not-quite-as-conscious thinking, so sometimes I have a cognitive habit or intuition that I remember was hard-earned through much evidence and thought, but I have to basically re-discover, re-prove, and re-articulate from scratch the justifications for things that I've been building on top of for years.
I have grown the skills for reshaping my own mind so much that my entire perspective on that is basically alien to the average person, impossible to word without several gated truths most are still "outside the gate" on; I can so often clearly see, once I know a person well enough, what cognition they could train and how, the way they could benefit themselves and the world by habituating certain ways of thinking, but it is inaccessible to many, in ways that make trying to convey it directly counter-productive.
As it concerns empathy and compassion - actually caring about the world and other people/minds, I have only exposed myself to ever greater levels of profound distress over the predicaments that we all find ourselves in.
Existential crisis. Already had one? That's okay, there are many different, unique ways to reach existential dread and despair, and in my experience exploring one rarely prepared me for the others, except in so far as it forced me into opportunities to train deeper coping skills.
Insufficient language.
The horizon of what I know I can't or don't know, or can't think, has for a few years now grown faster than my knowledge and thinking limits. I think they're intrinsically connected, such that any growth of the latter grows the former more.
I've had to start learning to be certain on-demand as a psychological tool, because in most issues that involve accounting for people, from my vantage point certainly as a genuine intellectual position is indefensible to the point of being unethical.
Understand, this is my unique experience. I don't know if yours will be the same. Maybe the problem isn't even mental growth, but my psychology which just wasn't prepared for growth that normal people handle just fine. I don't know. I probably can't know, not ever really with certainty, per point 10.
Don't get me wrong, it's fulfilling, and I think given the choice I would eventually push further. But I cannot stress this enough:
Were it not for my growing skills at not being emotionally distressed over genuinely bad things, at maintaining positive cognition in the face of genuinely real and immediate problems, I would be rendered non-functional by what I've built my mind up to do. As is I seem to experience nearly daily frustrations and distress that most people don't ever seem to, if I don't steer my mind correctly.
But who knows, maybe everything I experience is common and normal. Then again, if you can idea-fit anything sensical and relatable to you onto my words, that's the conclusion you'd be tempted to draw.
Doesn't matter. See, I don't actually care if I'm special or unique in mental growth. Or rather, I'd really like to believe that I'm not above average at all. If you really get it, then I think you'll understand this the most. Because the alternative, the possibility of really, genuinely being somehow qualitatively better that most other people, is not a pleasant thing. It is terrifying, lonely, and dreadful.
TL;DR: If one day you magically have the option to wish for profoundly increased intelligence, don't forget to wish for profoundly increased coping skills first.
