Can I be fired from parking my truck after work near a place that serves beer, can I be fired for this?

I pull oversized loads in TN. I was called and fired at 71 yrs of age, on the phone, last night, not because of my job performance...but because on an occasional day after work, I parked my truck across the street from the beer establishment.

I might have 1 beer once a week and go home a mile away. I worked for this mobile home hauled since 1987. I have done this behavior since 1991. Can I be fired?