WHAT'S THE MOST IMPORTANT THING YOU'VE EVER LEARNED

There's always room for one more

Challenging question, right?  when you took a look at that you started to turn the dial on your mental Rolodex to see if you could come up with a concept, a fact, an idea or a practice that you could fearlessly say, "This is the most important thing that I have learned."  You've read this far down on the page and you still haven't got the answer that will make you comfortable.  You've already whipped through at least three illuminations, or as they say in Kabbala, Emanations, and you are still not satisfied with what you've found.  You're even starting to feel a little uncomfortable and even a little peevish because you know that I would not be presenting a question without having an answer ready.  You're right, of course.  I will tell you right away that the answer that I have is more Zen, than anything.  It is something that I ran across today among some notes that I had scribbled some 60 years ago.  Those were the days when I could write, but had not yet learned how to read. :-) ...  So, yes, I do have an answer.  Yes, the picture you see contains a hint to the answer.  The caption also contains a hint to the answer.  Look, I can smell the burning rubber from here.  Relax, will ya!  Here's another hint, encapsulated in a short parable.  Stop me if you remember that I've told it before.  
I was waiting for a bus to take me home from the community college that I was attending.  I was 37 years old and had the opportunity to finally get a passing grade in algebra.  It was one week away from finals.  I was talking to a wise old Silver Eagle, classmate in algebra, telling him that I was going to change careers.  I told him that I was not worried, what with my masters degree and the six languages that I had come to know over the years.  He simply looked at me and said, When you get out there you will find dozens of competitors for the same work who speak 8 and 9 languages with twice the education.  Get ready.  The bus came and I went home wondering about the truth of the Senior Citizen's statement.
I did change careers.  I still do pretty well with a handful of languages.  I never put the statement to the test.  The world put me to the test with it.  It took me a while, but I came to believe it.  In fact, I came to see that it is true, not just for language skills, but for every single element of human existence.  You've read my mother's saying elsewhere on this blog, "You can always find someone worse off than you."
I'm here to tell you that every single day you can always find someone much better than you, at anything you might think you're the best at, in, with...you choose the preposition that fits.  That, boys and girls, ladies and gentlemen, aunts and uncles, Angels and Archangels, etc... is the most important thing that I have ever learned.  Why can I say that?  I can say that because it is the answer to today's title question, that is, "It is what I learned after I was convinced that I knew everything."
There's always room for one more, not just in the material world, but even in the confines of an arrogant mind.