Your discretionary income is that extra money that you don't have plans for after you must have taken care you your basic needs and monthly expenses. Some people use their extra money to gamble, club, drink, womanize and many more but it's wise for you not to use this funds for consumption purpose. Rather, invest it into bitcoin and save the value of your funds for the future.
Investing with your discretionary income allows you to pile up more bitcoin for yourself overtime and hodli till your desired time.
That's the truth. If people can spend their discretionary income on things that have no value and are not important, then it would be better to invest it in Bitcoin, which is valuable and will yield good profits in the future.
If there is nothing to do with the discretionary income, there is no need to save it in fiat, which will lose value over time, but Bitcoin is a better option. So, I think it is a good idea for those who know nothing about what to do with discretionary income.
Bitcoin for sure is like a better long-term bet than holding fiat that’s guaranteed to lose value. But for most, it’s not an easy mental shift, especially in the bull run like now.