After being married to my wife for about 10 years, who is from Germany, I found her one day eating vegemite on cracker biscuits. We've now been married for 20 years and she still has it on an irregular basis.
She is the first person I know, who has acquired the taste for vegemite as an adult.
When queried about why she had started to eat vegemite she replied, "that as I ate it so much, there must be something about it that was good".
So she and her Polish girlfriend tried it one day, the Polish friend didn't like it that much, apparently.
Apparently she had been earing it on the quiet, for about 2 years before I became aware!
Mick.