Thankyou!I think the notional concord works when their referent is a single entity which has been pluralized into units: five minutes is enough, five dollars is not enough.
But when the referent is a heterogenous collective of separate events, like classroom lessons, I just don't buy it, and find it sounds illiterate.
"My parents is the guiding force in my life." [No way Josť]
"Our Members of Parliament is a disgrace." [No way Josť]