If you're someone who is highly prone to stultifying bouts of nervousness, don't beat yourself up. First, doing so could make your anxiety worse. Second, you have a much more available scapegoat in human biology and evolution.
To put it very simply, nervousness and fight-or-flight reactions are physiological reactions to stimuli that our body wants us to watch out for. In the past, those dangers were sometimes mortal ones — dangerous terrain, flora, and fauna. Today, as ASAPScience explains, we experience the same "threat level" from things like first dates, competitions, and job interviews.
There is no one-way-fits-all to deal with your own nerves, as people fear different things, to different levels, yielding different reactions. But if you want to knock out some of the common situations in which nervousness arises, here are some tips on how to deal until it's over.