I bought one of the first books about XML, read it cover to cover; started writing my own parsers and generators, designed a custom XML protocol for a network server at work.

Then I had to live through the whole SOAP-drama, and Java EE; and ended up promising myself to never touch it again.

It has too many degrees of freedom for its own good, the C++ of data formats.

JSON is in many ways the other end of the spectrum; simple but underspecified and painful to deal with in anything but JS.

I often dream of something in-between.