Trickle down economics works.
But it works like a play in football; Only if every player does their job right. If any one player messes up the play can go horribly wrong for everyone.
The Rich have to spend extravagantly, investing in new ventures, creating jobs, upgrading at every opportunity, etc to pour the money into the economy to trickle down. They only do this when they see more money coming down the pipeline from the businesses they profit on by the masses in the lower classes. Basically they are a QB that can't take a hit, and won't stay in the pocket long enough to let the play develop. If they can stand in the pocket, deliver a strike down the field, and take the hit, it could be a TD. But instead they get happy feet, roll out of the pocket, sprint to the sidelines for loss, and complain about tax cuts all the way back to the huddle.
The middle class have to be content with their middle class status and be fiscally responsible with savings so that they can maintain their comfortable middle class lifestyle even in the case of an economic downturn. If they do not, the rich see the middle class's lack of spending capital and will stop spending themselves, drying up the economy. If the middle class becomes too ambitious and not satisfied with their status then they over extend themselves with risk and the middle class shrinks as the risk either booms and they move up or busts and they move down. The middle class has to stay strong to justify the role of the poor. They are an injured and taken for granted offensive lineman that doesn't have much loyalty to the QB, so holding blocks that split second longer isn't a priority.
The poor have to be upwardly ambitious. They need to be hustling in the streets, and taking advantage of the fact that already being in poverty they have nothing to lose by taking big financial risk with big reward. As weird as it may sound, the poor doing things like being frugal, and trying to save up what little disposable income they have, violates the play in trickle down economics. Its like a receiver who runs routes all game, and never gets a ball thrown his way, only to get discouraged. And then he get blamed for being lazy for not selling out to make the impossible hail mary catch at the end of the game.