I haven't attained it :)
There are some universals that one gets to understand as he/she gets older - one of them is how clueless one is at the young and tender age of 20. There is just no way around it and it's not a bad thing at all.
It's just true.
The reason it may not seem true - is that a lot of people, and I mean most, tend to carry shame and insecurity, which prevents them from growing emotionally, well into their 30s, 40s and even to their grave. As a result, it may feel like 'I'm not clueless at 20-something, I know better than a lot of the 30 and 40-somethings I meet!'.
To which I'd reply - you're right! They're ALSO clueless! Like you! :)
It's not a competition. It most definitely is possible to get a clue - and the clues will be different for everyone. The way to close up and remain clueless is pretty generic - remain defensive, follow the established rules, don't question too much.
The way to get clues is fairly unique, because you have to follow your heart and your gut, see how it plays out and adjust, a lot. That'll be unique to you, but not so unique that you can't find some helpful ideas along the way from people who've gone down a similar route and that you admire.
If you admire what a 20-something has done more than what some of the older folks have accomplished, it may be a sign that you need to look into what you want to get out of life, that takes more than a decade or two to accomplish. Dream bigger :)