Yeah, climbing shoe rubber can get old and lose its stickiness over time. Exposure to sun, heat, moisture, and just wearing them out can make the rubber harder and less grippy. When the rubber starts feeling stiff and doesn't stick to the rock like it used to, it's a sign that it's getting worn out. It's important to keep an eye on the condition of your shoe rubber and replace them when they've noticeably deteriorated. That way, you can maintain optimal performance and grip on the wall.