That's the simplest way I can tell him to describe where the difference is between people who do market activity and in everything.

The main goal may be the same, namely to expect profit for the trader and a large return for those who make the investment, but the way of doing it can lead to differences. The difference as we have mentioned. There are those who are greedy by putting in all the money (initial capital + profit) for the next trade without thinking about the opportunities that will occur in front of them so that the result is losing everything.
In real life it may be similar to in the trading world. They choose ways that go against the rules to achieve the ultimate goal.