Speaking about computer science - As technology progresses so fast, it takes a lot of time to master them. By the time you master something, another technology

Speaking about computer science - As technology progresses so fast, it takes a lot of time to master them. By the time you master something, another technology comes along obsoleting the old one. So, this is really a long long job race - you have to keep moving learning new stuff. Otherwise, you will be branded into a specific technology (like 'ios developer', 'php coder') and there's no way getting out of it.