Don’t aim to tackle big problems directly. Other people have tried and they remain big problems. Attack at the edges and you might get more traction than you expect.
Per Steven Levitt and Stephen Dubner - don’t set out to solve big problems. Big problems are well known about and nobody has solved them yet. It’s not for lack of trying. It’s that they aren’t easy to solve. What is easy to solve is little problems. Start Small. Little problems sometimes turn out to be the lynchpin to solving bigger problems. But hey, even if they aren’t a lynchpin, at least you solved the little problem.
If you’re clever enough, you can Reframe the Problem to Find the Solution through solving the right little problems.