It's not all about the experience you have or what you have learn't in school, but about how much you want to improve and learn...
Having a previous base of programmation helps a lot in this world, but I've seen much people that with effort, becomes a great robotics, even without previous kwnoledge on the matter.
Knowing how a PLC works helps as well to diagnose much problems, and I always recommend people who are interested to learn a few things about that.
The major part I've learnt was by searching throught the system variables, reading manuals and solving problems, nobody gets here with all learned.
When I started as robotic, even as I have received formation on the matter, the first thing I learn't was that I had no idea in reality...
This forum and people who are here also helps a lot, so many headaches avoided by doing a quick search, here and there, and when you discover some tricks you will become more confident about what can and cannot be done.
I've also coded some applications to analyze fanuc programs from an .ls backup, but it's a nightmare to parse all data and types of instructions.... I find sometimes new modifiers I haven't contemplated and need to do corrections.
I hope there was a way to do a quick search on the fanuc program for registers being used without the need to analyze all the program by hand, as I haven't found a way I needed to do it myself.
Maybe on the future I will publish it, but it's still in development and there are several bugs to address.