The song acknowledges real struggles—like losing a job or a home—but suggests that our internal reaction (our "happiness") is a choice.
Don't worry, be happy — не только жизненный принцип ... - VK bobby_mcferrin_dont_worry_be_happy_official_mus...
Do not worry about the events that take place in life just accept them and live your live as happy and worry free as you can. This I Believe The song acknowledges real struggles—like losing a job