A rough surface can hide how much useful material remains underneath.

Surfaces weather fastest, which makes them a poor guide to what is underneath. A board that looks grey and finished can be sound a millimetre in, and the roughness is only the part that faced the weather. The same mistake gets made with tools, with old houses, and with people who have had a hard few years. Appearance is evidence about exposure, not about substance.

When something looks past saving, test a small patch before deciding. Sand one corner, ask one question, try one repair. You are not obliged to rescue everything, but you should know what you are throwing away.