Internet doesn't help,either full of people talking BS. Doesn't have to be trading, look at any forum or discipline, e.g. bodybuilding, loads claiming they are ripped, lift 3 plates a side never upload a photo, many that do upload photos, are on roids but deny it. Other forums 'experts' just google something and change the text and pass it off as their own. I am on language forums and people claim (in English) they learnt fluent Chinese / Japanese in 6 months, its total bull. The average person thinks they have an IQ greater than 100 yet fail to understand where the value 100 comes from . Point is that you don't get caught out online so start developing a inflated sense of ego
I think getting older and you don't bother with the bragging and coming back to your original question, yes you need the passage of time, ups and especially the hards knocks for reality to set in.
I am approaching 50 and done a lot in my life but to be honest I am not gifted, just took decades of work, chipping away every day, getting frustrated, wanting to quit, self doubt etc.
No matter what you do, its just takes years of dedication before one day it finally 'clicks' and you can immediately see who is full of hot air or not.