Yes you can and you should. Sometimes it's hard to get ahead to learn stuff by yourself when you have a mind numbing job to go to.

But then maybe the person doesn't belong in to the world of software development.

Another problem is, when you learn something outside of work it wont be enough, because they want "commercial" experience.

Like when they are hiring mobile developers and ask: "do you have any successful apps on the store?"

If I would have any successful apps on the store would I be here doing this interview with you?