We might not have a money tree, but we can have a happiness tree. Dopamine, serotonin, oxytocin and endorphins are the quartet responsible for our happiness. Many events can trigger these neurotransmitters, but rather than being in the passenger seat, there are ways we can intentionally cause them to flow.
Being in a positive state has significant impact on our motivation, productivity, and wellbeing. No sane person would be opposed to having higher levels in those areas.