Must-be meaning "Must Be Nice" derived from B.C. days dating 2008 to 2010.
Sources confirm that the expression came from Jeffrey Johnston's work ethic.
ISRs come in late,
ISRs leave early,
ISRs take time off,
ISRs take a 2-hour lunch,
ISRs get a commission check,
ISRs take 2 lunches for the day,
ISR sales-kick offs,
If you are Jeff Johnston, Zadies for the ladies or Joe Lando
Working at a steakhoue
if you have Bill Ng's job or tattoo
Fiel got a new sticker on his BMW, Must-Be!