Earlier quoted context omitted.
It's because once I started doing it I found that I didn't actually know what I spent money on, not really. I found that my rough estimates for where my money was going were way off and lagged actual changes in my behavior by a number of months. Just as an example, I still don't feel like my family is spending close to double what we used to on groceries during the pandemic, but I know that we are because I have mont…
Do you put savings and necessary expenses aside when paid? To each their own. If it works for you great. I can’t imagine sitting down and tracking whether my grocery expenses fluctuated from one month to the next, since it can’t impact my ability to pay bills and save. If I was worried about not having money for groceries I would set that money aside when I get paid. I also have a family and am the sole income earner…
But I would also suggest that it seems like you're actually doing the thing you said you don't understand why people do. You have a budget, it just has a relatively small number of categories. But the answer to your question is that people do this for the same reason that you do your setting aside of money for bills, savings, and spending.