My regress to an average (or worse) developer did happen all at once, but I guess I'd say yes, because it was due to this same reason (jealousy/BS). Before "the event," many constantly did everything to get in my way and this slowed my progress down considerably. Years ago, I was on the cutting edge nearing greatness, but this BS eliminated any chance of me actually achieving that.

Also in there is my tendency to procrastinate, which also slowed me down, but I don't procrastinate much when it comes to writing code and working.