I've had an eyeshadow/blush palette for the better part of a year. I think the recommendation is to get rid of eyeshadow/blush after 6 months because of the potential of bacteria multiplying like rabbits. I use this palette almost every single day of the week, and it barely looks like I've made a dent. I hate throwing it away when it looks practically new, but is it worth the risk of eye infection? Well, I'm not getting rid of it tomorrow, or even next month. Maybe in June?
Why do bras become worthless after six months? Not that I've ever actually replaced a bra after six months, but they definitely get pretty stretched out and worn by the time I replace them. At least I learned this year that I don't have to wash them every single day. With that in mind, I replaced all my bras, bought new ones and plan on replacing them once a year. I guess. For not much material, and a design that has been used for decades, they sure are expensive. I spent the same amount of money on a new bra as I did on a new trenchcoat.
Those are the ones I can think of off the top of my head. What are your small annoyances?