“Does anesthesia change your personality?”

Anesthesia can cause delirium or agitation or drowsiness in some patients but only during the few hours after surgery.

Generally speaking no. In the elderly population it can unmask dementia. However, surgery is a stressful event. The stress or pain can manifest and heighten fatigue or even depression. There have been cases where people speak a different language or forget they are remarried etc., but those behaviors are rare and short-lived.