And before this gets too far off Traveller:
The PCs' merchant ship arrives out of Jump only to find that system control are quarantining them. So much, so normal on occasions. It happens. However, this time the quarantine period is a month rather than a few days or a week. At the end of the month it's extended to another month. Roll STY *now*. [Why, oh why, does the new Referee's Companion Sanity characteristic not get abbreviated to SAN????] [Did the writer fail a STY check?!]
Because some other game probably used that one. And Mental Equilibrium was to long.
(Look at all the 3D6-ish games that have chosen slightly different names than Strength, Dexterity, Constitution, Intelligence, Wisdom and Charisma.... wouldn't want to use the same thing.... (Others have done so using various clean room designs or SRD contents).
I think STY is terrible as well.
Back in the old days, in the rarely mentioned D&D 2.0 Players Option rules, they actually split each stat into two chunks (Strength broke into Muscle and Endurance, Intelligence broke into Reason and Memory, etc.) with the idea being that two characters who have a 16 STR might be 16/16 on the substats or 17/15 or 18/14. It was a neat system. But you needed quite a range of descriptors.
T.