When I first started diving I forgot a time or 2 to put the dust cover on my 1st stage when I got back from a dive. With the excitement and all the talk about the dive I stuck it in the rinse tank without putting the dust cap on. I did got back once and stick it back on a tank and purged it a few times. I never had a problem and now I am more conscious to doing it. With getting older I really make a conscious effort remembering to do it as soon as I get back on the boat or shore. I’m sure this is a common oversight.