Four questions that tell you if your spreadsheet is about to break.

You add a new row at the bottom of your data. Does the total at the top count it?

Yes, it updates on its own. No, I have to fix the formula. I have never checked.

The dates down the side of the sheet. Where did they come from?

A formula works them out. I typed them, or I dragged them down. I am not sure.

When you first opened the sheet, did it ask for permission to reach your Google account?

Yes, it asked me to authorise something. No, it just opened. I do not remember.

You want to rename a category, say “Groceries” to “Food”. How many places do you change it?

One. Everything else follows. Several, and I would probably miss one. I have no idea.