[JCoder58]

Scott Wlaschin's site http://fsharpforfunandprofit.com/ - For F#, but his articles try to answer the question "why is this useful?"

Eric Lippert's Monad Posts, starting at https://ericlippert.com/2013/02/21/monads-part-one/ - Uses C# to build up Monads using examples.

[kirse]

Seconding this. On a higher level also, what really helped things click for me was his "Domain Driven Design" slides...

Slides: https://speakerdeck.com/swlaschin/domain-driven-design-with-...

Video of talk: https://vimeo.com/97507575