Needles will wear out. The point will get dull / rounded. It just depends on the hardness, thickness of the leather the amount of sewing you do or repair work. I have had to replace a brand new needle after sewing one set of skirts off a dirty saddle. Sometimes you will notice a different sound when sewing. You can take the needle out and check it to if you think it might be dull or getting dull. I have sharpened them on a stone a few times and use the stone to know off a burr that you will get sometimes.