what's hardest many misunderstood aspect linq?

background: over unbroken month, i'll giving 3 talks during slightest including linq context c#. i'd know topics value giving satisfactory volume pleasantness to, formed competence tough understand, competence have mistaken sense of. i won't personally articulate linq sql entity horizon solely examples queries executed remotely controlling countenance trees (and wholly iqueryable).

so, have found tough linq? have seen terms misunderstandings? examples competence any following, nonetheless greatfully don't border yourself!

• how c# compiler treats query expressions


• lambda expressions


• expression trees


• extension methods


• anonymous types


• iqueryable


• deferred vs clear execution


• streaming vs buffered execution (e.g. orderby deferred nonetheless buffered)


• implicitly typed internal variables


• reading challenging general signatures (e.g. )