The nice thing between RD work is that there is always something new to learn. It doesn't matter if you have been in the business for 40 years.

I can pick up a lot of new ideas on my own, but communicating with other developers is a great way to speed up that process. Why? Because these other developers have already sifted through a lot of material, so the things they want to tip about it the best things they have seen. I just can't sift through everything published myself.

Next thing - it doesn't matter if someone have 40 years in the business. If you make a design, someone else (even if they are hardly out of school) can still suggest improvements. Maybe even huge improvements. That is a reason why there is a need for a two-way (and sometimes n-way) communication when managing a project. A manager that always "knows best" can be a disaster for a project.

People will only grow if you trust them. And if you look for a 50-year old developer, that developer will not have grown into an experienced and capable developer if someone else didn't trusted him before. The technology moves too fast for it to be realistic to sit at home with no connection to the outside world but a couple of magazines and expect to keep up. Having access to Internet will not make a significant change either - unless you are prepared for two-way communication. Sometimes talk. Sometimes listen. Evaluating. Giving feedback and receiving feedback. Without feedback, a developer (or any human being) will never reach their full potential. They may still be great, but not as great as they could have been.