Childhood is a mysterious age, where money drops from the trees like leaves..
In the film, Hitchikers Guide to The Galaxy (orginial BBC, not the dodgy Hollywood remake) the Golgrafinchams solve that problem by adopting the leaf as their primary currency.
Thus, if you are poor, then you just go visit a forest.
A joke it may have been, but certain Chancellors of the Exchequer didn't realise the irony of it..