I Am Smart Enough to Know I Don't Know It All

When I was much younger, I would have never said that I know it all, but I acted like I did. I had a strong sense of how the world should be and I had an answer for everything. My experience, is that age has taught me how much I don't know and how complex many things are. As a result, I know a lot less and am forgetting more of what I once knew with every passing day..lol
I do think that someone who acts like they know everything is struggling with insecurity and is uncomfortable with "not knowing".