How to get started with investing is both simple and difficult.

To say it's simple is because everyone knows how to do it, to say it's difficult is because it's incredibly hard to break the thief in one's heart.
Why simple? Because the predecessors in investment continuously summarize and share.
Why is it difficult? It's easy to get a summary, but it's not my own practical summary. I'm half skeptical and always want to try shortcuts.