The program who was to be a millionaire was on of the educative programs that time. It's not as common as it used to be because many activities have taken over and busy to watch it.
Back to the topic, naturally humans have this nature of greed in them with little or big(you can quote me wrong)
Starting from beginning God gave Adam and eve all the fruits but they wanted that particular one God said they shouldn't eat.
Now when it comes to money, it plays more there. You already have profit but you wants to get more. That's why they said the rich want to be richer
I have lost money sometimes just because i wanted more and eventually lost everything . Sometimes I mange what i have and it exceed even when i leave the market. Talking about trading here.
But like you said knowing when to be contented will really help.