My daughter (now 9 yrs old) has had this since she was an infant. In fact, I was suspected of scalding her tongue with her formula and had many of the pediatric nurses at her clinic giving me some evil looks because of it. LUCKILY, one of the peds there realized right away what it was and from then on, she was known as "the baby with the silly little tongue". Thank GOD they realized what it was and I didn't end up with a visit from child protective services!!!
In some people, when the tongue goes crazy with the lines or circles and whatnot, it can get a little sore. My daughter's gets a little sore every now and then, but it's fairly rare for her and it's nothing unbearable or anything.
Also, according to the pediatrician who diagnosed her, for some people it can actually be a way of telling if you're about to get sick! With my daughter, even since she was a baby, when hers "went silly" as they put it
we KNEW she was getting sick.. and sure enough, within a day or so, she would be coughing or sneezing or just generally ill feeling. It's still that way to this day..
So, you're completely normal
nothing to worry about at all!
Geographical Tounge?? HELP!! 
