I tend to focus on core concepts quite a bit more than actual examples, so that the fundamental understanding of what the examples are trying to teach me is building on skills I already have just haven't figured out how to use yet.
tl;dr Your mileage may vary. I learn kind of counterintuitively for others.
Since this seemed to be popular, I decided to make a repository for content about haskell topics that you can find here new materials for lens will be put here
[SPJ talks about Lens] (https://skillsmatter.com/skillscasts/4251-lenses-compositional-data-access-and-manipulation) (Requires you to login, but is free to make an account)
This was one of the biggest influencers to me learning how lenses are supposed to operate.
[Creator Edward Kmett talks about Lenses, Folds, and Traversals] (https://www.youtube.com/watch?v=cefnmjtAolY&feature=youtu.be&hd=1)
[The Unreasonable Effectiveness of Lenses for Business Applications] (https://www.youtube.com/watch?v=T88TDS7L5DY)
Great talk about how the various components of lens are used. Highly recommend this talk once you have a basic understanding of how lenses are meant to work.
[Lens over tea] (http://artyom.me/lens-over-tea-1)
Shows about how to build lenses up from nothing and why they are useful to the everyday programmer. (I need to finish this myself. Damn ADD)
[From Lenses to Yoneda Embedding] (http://bartoszmilewski.com/2015/07/13/from-lenses-to-yoneda-embedding)
Talks about Comonads and how lenses fit into the whole big picture. Another one I really need to finish reading all the way through myself, but it does explain some (if not all) of the category theory behind lenses.
[Intolerable] (http://intolerable.me/lens-operators-intro/)
Not really meant to be an introductory material, but it does provide a neat reference with examples for how the most used infix functions of Lens.