I get notifications on my phone whenever I use my bank card and this week, while undertaking a mini-audit, I noted that I was doing something that apparently leads to financial ruin. The other morning, in a bakery on Broadway, I spent $8.70 on non-essential pastries. A few hours later, in spite of the loaf of bread in my house, I threw down $8.25 at Pick A Bagel. And scattered throughout the day, like small distress flares sent up from my current account, was a notification trail of $3.77 coffees.

Suze Orman, a personal finance expert with her own show on CNBC, said something in March that resurfaced this week and made everyone instantly furious. “You spend $1 to $3 on a cup of coffee,” she said, “which is approximately $100 a month … $100 a month in a Roth IRA [retirement account] over 40 years is $1m. So you need to think about it as you are peeing $1m down the drain as you are drinking that coffee.” It’s an escalation of the avocado toast debacle of 2017, but now they’re coming for your coffee.

It’s not the first time a wealthy investment analyst has characterised coffee drinking as feckless spending. A few years ago, Shark Tank judge, billionaire wealth manager and nightmare human being Kevin O’Leary told CNBC: “Do I pay $2.50 for a coffee? Never, never, never do I do that. That is such a waste of money for something that costs 20 cents. I never buy a frappe-latte-blah-blah-blah-woof-woof-woof for $2.50.” Instead, he said, he drank coffee at home and invested the difference, as a way of “maintaining growth in my own personal investing”.

Most of us understand this to be a narrow definition of personal investing. You definitely don’t need that coffee. Nor do you need brunch of any kind, ever. You don’t need to go to the movies when there’s TV at home, and why have kids when you could maintain growth in your personal investing by putting the money in a Roth IRA instead? The gimlet-eyed joylessness of an old age spent reliving all the wonderful ways in which you saved money is certainly one to look forward to. O, reason not the need.

On the other hand, I’ve always liked Orman and quite admire her for doing the maths on this. In other circumstances, most of us would not, probably, reserve a whole lot of love for Starbucks and might even admit the chain is bleeding us dry. For all that Orman and O’Leary are advocating self-denial in the pursuit of making more money, the puritan in me quite likes their jabs at consumerist spending. Iced coffee season is upon us in New York and the sheer volume of people wandering around sucking on straws like pacifiers is a reminder of just how bananas many of us are, nursing an apparently constant need to be consuming all day. I went to a meeting on Tuesday and although I was running late, I swerved into a coffee shop on the way because for some atavistic reason that might once have been fixed by smoking, I wanted the security blanket of a large, sweating cup in my hand. It was a nervous tic, and not a particularly good one.

It’s not the money I resent, although there is that. It’s the consumption as blind reflex and the equation of that reflex with comfort. No matter how unpalatable the source of the advice, it might be a good idea to take another look at the habit.

• Emma Brockes is a Guardian columnist