Not impulsive yet, but the next Backstreet Boys cruise is going on sale 1/7/14 and I'm already actively figuring out a way to afford it. I now I should not book it and will try not to, but it will be really difficult.
Last two cruises I kept telling myself I wouldn't book until I'd be sure to be able to afford it, and both time I booked during the first week. And I've realized I'll have the money for the deposit! Resisting will be so difficult!