MySQL has quite a few surprises like that. Things that are quite hard to do in other DBs that it makes easy. Look into GROUP_CONCAT, for example. Amazingly powerful.
On the other hand, it has some holes (especially in how capably it uses indexes) that you can fly 747's through.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.