Making new friends at nineteen feels harder than it did at six. Mostly because at six you just asked.

The mechanics did not change, only the self consciousness. At six you walked up and asked, with no theory about rejection and no concern for how it looked, and that directness was most of what made it work. Adults run the same request through so much calculation that it often never gets made.

Try the six year old version once this week: ask somebody directly to do a specific thing at a specific time. Expect a few people to be busy, because that is arithmetic rather than a verdict. The asking is the whole skill, and it comes back quickly.