What, no feelings? The surgery can be performed either under general anesthesia (asleep) or local anesthesia (just your thumb). Either way, you should not feel any pain other that a small needle stick.
Anesthesia. Options are being awake or delayed along with a local nerve block, or being fully asleep. Don't worry, while there may be some small things along the way that are uncomfortable, you won't feel the surgery. Hope this helps!