Fortunately, what I have retained is the ability to pick up almost any subject and learn about it on my own. That's more important than anything they can teach you in a classroom.
For my sins, I became very addicted to Shades on Prestel back in the day. Due to this, I prefer MUDs that are not deep on class progression, and just easy fun.
A lot of the still running MUDs have deep learning curves, due to some of them having been running for a good few decades. To the new or casual player, this makes them impregnable.
Whereas I don't think we need to change the beauty of the text based medium, I do think that the genre needs updating to make new MUDs more accessible.... Even D&D finally accepted it needed to simplify again to gain new players.
Get some proper hiking boots!
And yet we rarely ask or say "maybe I should just eat fewer calories?" Unless you have some other disorder that prevents normal bodily function, that does work (and would be viable I'd imagine for the majority of people being prescribed).
But it requires patience and discipline which are basically non-existent for the majority of the population.
As a thought experiment, imagine what you eat per day. Now halve it. Would you be having a good time?