Just recovering from the same. Caught it from the hospital of all places.

I thought that my body would be very immune due to frequent trips to the subcontinent.

I have come to the conclusion that there is no norovirus in India and that my immune system is hopefully still intact .

On a positive note , one does recover fairly quickly from noro with just simple rehydration. Unlike the Indian gastrointestinal infections which are frequently bacterial or amoebic and need antimicrobial therapy.