Some people uses the lyrics to remember where to activate, because yes, some songs might be harder than others to remember (especially when 200th Green for example). Alot of tricks can be used to easily remember them. The hardest part is to learn a path, once it's learned, you'll activate automatically. XD
First time I tried pathing, I said the same thing as you, literally :Not worth the effort. But then, once I tried more, I've seen a significant score improve, and I've been able to GS (even get 1sts) that I never thought I'd be able to get, just by remembring a path. Since then, I try to path the songs I want to get a good score on.