A much better way would be to think of specific examples (of times when they were on time or late for an appointment, for instance).

This risks running into salience issues. Events which lead to failure or loss of status tend to be a lot more salient than those which lead to success, and while that by itself could still give you a reasonable if upsetting metric, I don't see any obvious way to control for differences in how this tendency manifests, or for differences in salience between domains (which could paradoxically lead to overweighting failures in a domain the testee considers personally important). Differences in general recall ability would also weight the results, but you could probably control for that with some extra effort.