I am a new developer, who just got hired at a big company. I don't know how but I guess they are desperate. However, I am well-versed with HTML5/CSS3 though things change and new things are released and I keep up with as much as I can. But this job required me to hand-code Javascript, know Jquery and Ajax. I have been exposed to this a bit but I am not sure if I can hand-code Javascript.

My question is, is it necessary to memorize all there is about Javascript or are there a few key things that I should know how to hand-code because looking at javascript code it seems there are lots of lines code!

Please point me in the right direction.