Same here. I've never had a problem with illness on a cruise and I attribute it to my fastidious approach to personal hygiene. I will oblige the crew when they 'urge' me to put sanitizer on my hands when entering the dining room, buffet, etc., even though I know it has little or no effect on killing norovirus. What is more important to me is washing my hands often, with hot water and soap, and for more than just a few seconds. I also try to avoid touching handrails and elevator buttons. I'll gladly let someone else ask me which deck I want and let them push the button!
I also use the backs of my hands and fingers when possible, since they are less likely to make contact with my mouth or nose.