Lames excuses about having better things to do usually turns out to be an exaggeration, if not an outright lie, too, because when people tell you that, then you hear what they ended up doing, you just feel sorry for them for having to have gone to that length to lie to you about their future exploits, then to have their bubble bursted and end up doing the sad thing they ended up doing, which is actually what they were talking about when they said "better things do do" initially.