Wasting 3 years on failures, instead of a month
Why? I think there's a big disconnect between what people imagine as "hard work" and what actually happens during "hard work". A lot of people watch movies and imagine the training sessions in Rocky or when Batman was down in the hole in TDKR to be what "hard work" might look like. Imagine a movie about a guy who wants to improve his dating life, he gets rejected 4 times in a row by a girl and on the fifth time he pulls it off because of a dramatic mindset shift (cue epic classical music). I think poor and middle class people see that in a movie they go "Well duh that's a movie. Not realistic at all. This type of shit never happens, I'm not going to fall for fiction."
The fact that people think putting yourself through this would make them seem like a dude with issues... and how it would be embarrassing for others to find out
Surely conventional wisdom tells us its a really bad idea for people think we are weird, or obsessed, or desperate, or emo. So we don't do things that might compromise our position, for fear of losing social standing. Do you always wonder why every successful Hollywood actor has personality issues? This is why.
But when you ask successful people what hard work is, they know firsthand about a lot of things that definitely wouldn't be cool to see in a movie. Instead they will imagine a guy who is a loser who has been an outcast his whole life, never got a date in High School etc... but they know that if this dude becomes successful there was a lot of bull shit that he had go through... and all of that wouldn't fit in a movie.
What would be that prolonged era of shittiness? Well if we're going with a dating example, it would be somewhere around being called a creep at least 500 times before getting a date. If we go for a sales example, it would be starting the day at 6 am and staying out past 9 pm everyday. Sometimes you go to downtown lounges and networks until 12. And if they cry after a day of flakes, missed closes, and being spat on, well that's actually normal. They would be like "Oh yeah I totally had to go through the same thing when I was in your position". And laugh about it.
And develop a perverted relationship with pain
It teaches you that list of justification is pretty ridiculous. It's a bunch of beliefs that we have built up ourselves, sure society and family can influence the direction it takes, but the more you believe it the more you reinforce it.