I used to parrot the common advice to spread your money across many funds from the start. But when I did that with my first $1,000, I didn't feel connected to any of it. So, I moved it all into one energy stock I understood, and watching its price moves taught me about risk and research. Now I believe starting with one thing you know can build confidence before you diversify.
Just like I don't only collect one country's stamps, I learned not to put all my cash in one stock. It helps if one part drops, the others can still do okay. (I started with a couple cheap sets and added more over time.)