It means you don’t risk more than you’re comfortable with losing on a trade, you don’t trade when there’s no obvious setup present, you don’t let your elation or anger influence you to jump back into the market right after a win or loss…you don’t do these things because you have self-control. Don’t worry about the money in your trading account, just worry about the process of trading and about becoming a good trader. It does not matter if you have $300 or $30,000 in your trading account, if you can trade you can trade, and it won’t take long for a good trader to build a small account into a larger one.