For me, I feel like the most notable piece was the fact about an owl's neck/head-turning. I'd always thought that feature was exclusive to owls and never realized how that's a trait found throughout most bird species. I also found the tidbits about owl skulls and how their eyes are fixed in place a lot of fun. Especially when I connected the dots and realized that was why they turn their heads so much.
In terms of actual, whole course segments, I found the section about owl calls to be a ton of fun. Hearing all those different sounds really endeared me to some species I'd never really thought about before. (Mainly the Black-and-White Owl and how it sounds like it gets startled at the end of its call.)
I've unfortunately never seen a wild owl. But, I have seen some kept as ambassadors and as rescues at my local animal sanctuaries. Those were mainly Barred, Great Horned, and Barn owls. One December I did hear some Great Horneds hooting a ways off which has been the closest I've ever (knowingly) gotten to a wild owl.
While the captive birds were just as lovely, there's something breathtaking about seeing a more mysterious/rare animal out in nature.