Just like when you go to the mechanic and the car is fine.

Glad he ate for you.
What did you bring him to the store in? The box?
Maybe being in a small enclosure made him feel secure enough for his appetite to get his attention.

The reality is if the ambient temps dip below lower 80's in the winter, many will go off feed or eat sparingly. In a tank security, temps and humidity(also important) can be real difficult to control especially come winter time.