I agree with you that the important thing in bitcoin investment is the amount of income you earn and also the amount of bitcoin you are able to accumulate from it,
It is not the amount of income that you earn will determine the amount of bitcoin that you will accumulate but it is the amunt of your discretionary income that will determine the amount of bitcoin you will be able to accumulate overtime if you invest with a focused and committed mindset.
Yeah I know where you are driving at, the aspect of the amount of income one earns will determine the amount of bitcoin to accumulate. Actually I was not the one that made the statement but I replied to what @Felicity_Tide said, and there is no much difference from what you are saying from mine. Discretion fund and or amount we earn from salary are not a seperate thing because without the amount someone earn from his place of work or anywhere he gets his fund from, he can't be able to have a discretion fund because there must be a place you earn money to invest in bitcoin and also have a discretion fund so both are thesame thing.
Income and discretionary income are not the same thing, even though you might be describing something similar, but the concept of discretionary income is the amount of money that you have left after you account for your expenses. It is more accurate to say that we are ONLY investing from our discretionary income rather than just presuming that two people with the same income are the same or presuming that merely if someone makes more money or less money that he is able to invest in bitcoin or not. Sometimes people have discretionary expenses too, so if they cut some of their discretionary expenses, then they end up having greater discretionary income (more money available to buy bitcoin). Of course a person who chooses to spend 100% of his discretionary income on buying bitcoin is likely going to end up getting himself into trouble due to miscalculation of his expenses or even sometimes realizing that he needs or wants thing, so sometimes even within discretionary income there could be things that a guy wants to be able to buy from time to time or to prepare for some extra discretionary expenses through the month like going out to eat, drink or go to a movie. and so if he has spent all of his discretionary income on bitcoin, he might create some worse existence and stress for himself and perhaps even get into a position that he ends up having to draw from his bitcoin because he did not lessen his level of BTC buying aggressiveness.
You're totally right. There's a very huge distinction between the discretionary income and a person's income, but people often get confused and use the both concepts interchangeably, which is very wrong. While a person's income is the total amount the person usually earns at the end of the month, week or whatever interval it takes for the income to come in, the discretionary income is different from the actual income as it's what you've got left with you after covering majority of your essential expenses, and thus, this is what people should often use to invest in Bitcoin.
It's always important to make that distinction between the both concepts because two persons may actually have the same income but due to the differences in their expenses, priorities and preferences, their discretionary income may differ.
And since the discretionary income is what is often used for investment, it's important to note that, one should be able to adjust his discretionary expenses effectively, in order to free up funds to invest in Bitcoin.
But just as you've rightly pointed out, blowing one's entire discretionary income on Bitcoin could be seen as going overboard, due to life's unpredictability, unexpected events could come up at any given time, and it's important to create room and resources to weather these events whenever and if ever they come up, or maybe you just wanna take some time off to enjoy life a little, go for dinner or movies, etc.
Blowing one's entire discretionary income on investment can potentially lead one to financial stress, pushing them into tapping into their investment when the investment isn't even matured or at the desired status, well of course the person in question has a solid financial back up to weather such events. But still, it's not advised to spend 100% of your discretionary income on investment, instead you could split the discretionary income between bitcoin accumulation and solidifying your financial back up even more.