The change is very real, and it is very fast. You are addicted with your first time, and it is a very strong addition.
Meth is probably the second most common drug behind pot. There are arrests here and in Chattanooga for both all the time. I live on the south side of town (old, run down, poor) and several of the busts are in my area. You don't see people standing on the street selling it as this is still a small town (45,000+), but it is still there.
Southeastern Tennessee was the nation's top meth producing area not long ago. I think we have slipped a few notches thanks to public awareness and the Tennessee Meth Task Force.