“I was a halfhearted, at best, rebel”

Simplified Meaning:

The person speaking is saying that their efforts to go against rules or norms were not very strong. They tried to be different or resist authority, but they didn't put much energy into it. Imagine a student who wants to skip school because they think it's cool, but instead of actually leaving, they just daydream about it and stay in class. In history, think of someone who talks about wanting to change the world but never actually joins a protest or takes meaningful action. They have ideas that might challenge the status quo, but they don't really do anything significant to make a change. People can take this as a lesson about commitment. If you believe in something strongly, like a cause or a personal goal, you should put your full effort into it rather than being half-hearted. This way, you increase your chances of making a real impact or achieving your goal.