In all my years (25+) working on electronics I never once used a grounding strap or anything and only once, have I damaged a CMOS chip due to static. It was obvious at the time as there was an actual spark that jumped between the IC and the board that it was being inserted into.

That being said, RAM chips (any kind - includes SD, USB, etc) are prone to eventually fail as they have only so many read/write cycles that they can perform (most modern RAM list the cycle number in the spec sheets). I know several people are working on the issue and are trying to increase the number of cycles (never mind new types of memory).