This is not really true: once you have spent your money, it may stop being sensible to go on with the 'thing': buying a ticket for something in the future. You

This is not really true: once you have spent your money, it may stop being sensible to go on with the 'thing': buying a ticket for something in the future. You have spent the money but you are under no obligation to 'perform' it. If it sucks, you had better lose your money and not waste your time than both.