For my building friend Darren who buy a cup of coffee and sanwiches every day on the way to work.
If he spends £3 per day having a coffee on the way to work. That's 45 weeks x 5 x 3, a whopping £675 pa
If you invested this sum of money at in the stock market over 20 years it would be worth between £18,000 and £28,000 assuming modest returns of 3% to 7% pa.
All for the price of a cup of coffee. Take a packed lunch instead of another £4 for sandwiches plus a drink and calculate what he could save.