I've recently been hired as a *software engineer* at a small (about 60 people) and nice company. I have 3 years of experience (at two companies - one of which was a multinational one), and I have just graduated this year. I'm worried because I have some work colleagues (most of them) who have **A LOT** of knowledge about several technologies and I don't. 

I know only the basics of those technologies as I'm still pretty young (network related technologies as in Network Management Systems) and I just keep reading and learning to be at the same level as they are, but I'm a bit concerned that they can hire someone with more experience.

When it comes to programming, I don't have any reasons to be worried as I know that I can handle things (it has also been proven at the technical interview) but when it comes to networking, I'm just trying to do my best to keep up with my colleagues. 

Should I worry about being replaced with someone that has more experience than I do? Does age matter in this situation? How can I get rid of this *fear*?