DJing, like any other skill, is something that degenerates when you fail to practice.  You may remember the theory and ideas well, but the technical aspects of performing will slowly degrade when you fail to focus your attention towards it.  It can be difficult for an old DJ to keep up with the times, because the technology behind DJing seems to change very quickly.  You will see it all the time if you know working DJs.  They will have piles of gear that is no longer useful or at least it seems that way.  A pile of CDs aren’t going to help you when you really need mp3s.  You could spend weeks ripping those songs back to a usable format. Adding software seems to compound that problem even more.  Traktor’s layout can be difficult for anyone to start with.  Instead of being able to recognize functions by the way they look, you will spend time digging through menus and trying to figure out what each of them actually mean.  It sort of seems like going from Microsoft paint to something like Photoshop.  It can be daunting, but it is not impossible to transfer from software to another. http://www.digitaldjtips.com/2014/11/questions-im-returning-dj-struggling-digital-gear/