I think you are leaving out #4. You need to have basically unbreakable confidence. Dealing with that horrible plateau that we all go through often breaks adult players. This [1] is Magnus' rating chart. It looks like an unstoppable line to the top until you zoom in and actually look.
In April 2004 Magnus was 2552. 15 months and 162 classical games later he was 2528. When a 'normal' adult plays 162 classical games, which is often only done over a period of many years, and only loses rating points, they assume they've hit their peak and their spirit breaks, or they try to 'fix' their training routine and just end up completely breaking it. This is one reason it's so much easier for children to improve - they [usually] don't really think about such things in the same way and just keep grinding away.
Chess improvement is brutal. You don't put in 'x' effort and get some proportional reward back. Chess improvement is very stair-step, you wake up one day and you're suddenly much stronger than you were the day before. But until you hit that next stair-step, you see little to nothing.
In my own case I only learned how the pieces move as an adult, at least in so much as 18 counts as an adult, and feel I've gained at least a moderate level of unconscious mastery - around 2600 bullet and 2500 blitz, with the overwhelming majority of that improvement coming well after 30, and I'm still improving!
In April 2004 Magnus was 2552. 15 months and 162 classical games later he was 2528. When a 'normal' adult plays 162 classical games, which is often only done over a period of many years, and only loses rating points, they assume they've hit their peak and their spirit breaks, or they try to 'fix' their training routine and just end up completely breaking it. This is one reason it's so much easier for children to improve - they [usually] don't really think about such things in the same way and just keep grinding away.
Chess improvement is brutal. You don't put in 'x' effort and get some proportional reward back. Chess improvement is very stair-step, you wake up one day and you're suddenly much stronger than you were the day before. But until you hit that next stair-step, you see little to nothing.
In my own case I only learned how the pieces move as an adult, at least in so much as 18 counts as an adult, and feel I've gained at least a moderate level of unconscious mastery - around 2600 bullet and 2500 blitz, with the overwhelming majority of that improvement coming well after 30, and I'm still improving!
[1] - https://ratings.fide.com/profile/1503014/chart