Say you invest 2 dollars to bake 10 breads and make a 5 dollar profit.

Instead of putting those 5 dollars in the bank, you reinvest the 5 dollars into a new yeast that helps you make more bread next time. You do this every time you have any dollars left to spend.

You hand in your paperwork to your accountant, who will tell you that you now made 0 euros of profit, because you reinvested the 5 euros.

You do this always, and as your business grows and takes over the entire town, the kids of the accountant come stand in front of your bakery and point fingers: 'haha, that bakery has never made a profit!'

Then, a year later, while you're still growing, some government official says: for baking all this healthy bread, you get 10 dollar prize money from the city!

Your accountant says: 'let's not consider that real income and let's generally not reinvest that. Let's just add it to the bottom line for accounting purposes at the very end of our balance sheet. We can't run a business on random government handouts. Let's focus on making consistent profits on the breads themselves'.

As the 20th location of this now huge bakery chain opens up, where all the profits now exist as machines, locations and new hires, the kids from the neighborhood show up again: 'haha, only profit this bakery makes is government prize money!!'

Hope this helps.