i believe u are referring to the quote 'tommorrow never comes'??
well, it actually means tommorrow wont come when u say ' oh, ill do that tommorrow'. not literally....
so, like, when u have to study for exams, you sometimes say 'stuff it, i'll do it tomorrow'. and then the next day, you lose interest and most-likely say 'oh, maybe tomorrow', therefore, tomorrow never comes, as you always say tomorrow, but you never do it... tomorrow....
does it make sense?
sorry, lol.
hope it helped!!