I think my biggest Ukepiphany was the insight how crazy different classical and modern music are from each other.
When I learned the Songs for the April and May Challenges, which were Prelude in C nd Yesterday respectively for me, there was such a huge difference in time necessary to learn them it blew me away. I grinded away at the Bach piece for weeks just to memorize it and even more to be able to play it halfway clean. When I started learning Yesterday immideately afterwards, it only took me two days and I was done with the whole Song.
This was quite the experience for me. My learning capacity has noticibly grown by that and I am now far quicker to memorize pieces structured in a modern way 🙂