Anyone that uses all his money that he has to buy bitcoin is a gambler and will end up selling his bitcoin at loss when he needs the money to solve his problems. You can only invest with the extra cash from your income aftee taking care of all your basic needs and monthly expenses.
I completely aggry on this,
because the strength or backbone of any successful investment especially long term investment normally depend on the backup funds you have.
It is certain that after investing, challenges, family issues must arise and when you have no emergency or backup funds you end up falling back on your investment, perhaps selling it at lost just to meet up problems at hand.
Therefore it is healthy having a backup funds while investing, thus, it fuel patients in achieving success in bitcoin investment.