What exactly are you saying, do you mean that if one is using his discretionary income he or she will still panic and if his not using his discretionary income but is determine he or she won't panic, sometimes you people should try to make things very clear to people when writing and stop confusing people.
I think you're the one that is getting yourself confused here, I don't mean to dispute on the fact that investing from your discretionary income means you're Investing with peace of mind but even as that one also need to be discipline so as to enable you stay focused regardless the ups and downs of the market. Because alot of people have been investing from their discretionary income yet they don't feel comfortable when there is a little drop in the value of bitcoin simply because they are not well discipline so when investing from your discretionary income is also advised to apply self discipline this would help you to stay focused no matter anything.
Maybe they are not comfortable with those situation since they are actually not prepared. But if it happens that they made good preparation like set up their emergency funds then provably that those volatile situation can't affect them.
Usually we encounter those sentiments on new investors on the scene. They get panic if there's market correction happens, but those who have experience with Bitcoin those situation is just a normal scene and instead of getting panic on these situation they usually buy since that is good opportunity for us to accumulate more Bitcoins.