I receive my "oh wow" when i do the same things in Postgres like in MySQL: Writting some procedures, triggers and use foreign key. The "oh wow" was that it just *works*. After some years of using MySQL this is a very uncommon feeling, even if you are experienced which MySQL. ;)
I'm going the other way -- I first started SQL/RDBMS with PostgreSQL, and now I'm starting to have to deal with MySQL for some things at work. I know exactly how to do what I want in PG, but doing the same thing in MySQL is ten times more complicated and has me pulling my hair out :(
