I know that discretionary income is the leftover money after you have paid for monthly expenses, and you are allowed to use your discretionary income the way it pleases you. I still believe using your discretionary income to live a lavish lifestyle will drive you to sell your bitcoin too early. For example, you can go to a club and mistakenly spend way more than your discretionary income, and if you don't have any other money elsewhere that you could use to complete the money in your hand and pay for the extra expenses you incur in a club in the process of living a lavish lifestyle with your discretionary income, it can drive you to sell your bitcoin too early to pay for your bill in a club so that you could go home and rest.
As an investor, it is very important to have knowledge of money management, to know what you want, how much should be spent, and the amount of money that needs to go for investment. If you pursue a lifestyle that you cannot afford, you may end up being unable to make any investments.
Most Bitcoin investors don't know how important good money management skills is when it comes to Bitcoin investment, they thought that it's only the poor that needs it, but they don't know that it's really important for an investor to be good in managing his money, either the rich or the poor, because a good money management skills is what's defines a Bitcoin investor, if he is going to be successful on the longer run or not.
Just imagine that an investor start investing which money meant for his basic needs or he invest without putting and emergency and reserve funds in place, just in case of emergencies, he is doom to fail, so a good management skills is highly needed if an investor want to be successful in his investment.