Btc is cup money is liquid the water and Banks are from the word like a River bank.
So money currency is water and btc IS the cup all assets gold btc and other crypto are the cups where the money the water flowing in.
Those who got cups to collect the water when it's raining those got most of the water so to speak they got most of the money.
If u sell btc early it means you empty your cup ...btc is big cup small coins smaller cups they full faster then biggest cup the bitcoin.
Those who got cups when its raining they collect the most of the money more water more cups needed to collect water.
For a moment think that the other person do not know anything about Bitcoin and giving such examples will further confuse him.
To start with, you should tell that Bitcoin is digital money and try to compare it with paper money. This way the person may understand quickly and may not remain in the puzzle. After giving some introduction of Bitcoin, you can give him some basic Bitcoin videos or article links and if he/she will be keen to know more about it, they will definitely study about it.