This infamous answer on StackOverflow have reached meme status. The question is about finding opening tags in XHTML using a regular expression, and the answer makes it abundantly clear that this is not possible - and you will surely go mad if you try.

Casts are confusing in C#. The syntax itself is simple: (Bar)foo casts the value foo to the type Bar. But this means two very different things for reference types and for value types. For numeric value types, a cast performs a data conversion