That's basically all my act is - it's just listening all the time and watching for what people do with their hands and so on. It gets on people's nerves a bit - especially when you're at a wedding and you're scribbling on a table and they go 'stop doing that' and you go 'I can't.'
In the modern world, the anxious temperament does offer certain benefits: caution, introspection, the capacity to work alone. These can be adaptive qualities.