Here's the secret:

They do not need self discipline. It is automatic for them. It does not require any additional effort to force their brain to do something. It is how their brain works.

The problem is that they tried to make you feel like a failure for not being able to do the same. This is like tall jumpers blaming your supposed lack of discipline and effort for not making a high jump when you're 5 ft.

It is accepted that short people cannot jump as high and nobody will blame you for not being able to do it.

When it comes to brain differences, there is no acceptance. You get tolerance at best.