Regarding getting familiar with new technologies and new topics

[simrananand-2-11]

I saw few talks of yours and other developers who spoke at same conference you talked at. Also listened to few talks to some other conferences. My question is how do you come to know about things you talk at conference? I mean web performance scalability all these terms are new to me and I was amazed to see that people talked about them as if they breathe it. They were quite confident about what they were speaking. How do you get this confidence in these things which are not so common? How do you know that this new thing has come? And how are you so sure that these are its negatives and those are its positives?