Like onions, some varieties do better in heat than others. There is a site that has instructions and scrumptious pictures of beautiful garlics:
http://www.gourmetgarlicgardens.com/growsouth.htm
I may try a few different varieties next year and see whether I can really distinguish one from another. I can distinguish different kinds of onions, so maybe I will be able to tell differences in garlic.
I know that for some things, I really can't tell the difference. Wine, for instance. I occasionally drink wine and when I do, it would be a decent Beaujolais or a nice white wine.
I'm awed and amazed at people who have the expertise to not only distinguish different varieties but some who can actually guess the year the wine they are tasting was made.