My daughter had her surgery at age 5.  She doesn’t remember a thing (she is now 14.5) and had no complications.  She recovered beautifully although some of her stitches ripped out due to her running around too soon. (Good luck trying to keep her still for a couple of weeks afterwards for everything to heal)

She was very mature for 5 and was explained everything and still wanted to go through with it. (I understand that she was only 5 and probably couldn’t absorb all the information)

Went back for an exam under anesthesia last year and will not need any more surgeries.