I don't know if learning how to ride a skateboard would fall under the category of meaningful, but it is the first thing that came to my mind when I thought of a significant learning experience.
6 years ago, I went to New York for the first time to visit my cousins. While I was there, my dad bought us a skateboard called "The Wave", which at the time was something that only the "cool kids" had. That same day, my dad took my sister Daniella and I to a park so that we could ride it for the first time. It wasn't as easy as the guy at the store had made it seem.
I remember falling, and falling, and falling. I watched my dad ride it; he
held on to me as I tried, and explained the technique to me 50 times, but after an hour, my sister and I just kept falling. It was when I finally managed to stand on the skateboard for 2 seconds - after two hours of falling - that I realized how life isn't meant to be easy, and that no one magically knows how to do everything. At some point of our lives, we will all struggle to learn things, but it is those that overcome the frustration linked to failure that achieve great things.
I kept practicing and practicing that day, I practiced almost every day since then. And it was worth it, because now, riding "The Wave" is like riding a bicycle for me, it's something that regardless of how long you leave it aside, you'll still be able to do.