I don't know much about pareto past the 80/20 rule, but it seems to apply to the learning curve
You look at fitness, which I like as an example because it's the easiest to visualize. The first 20% of effort sustained over time (working out 3-5 hours a week) will get you in shape, looking good, feeling good
Same thing with fixing my car, I learn how to changes tires and oil plus do small shit, saves me the majority of the trips to the shop
Basically the rule I follow is give that 20% effort for useful auxiliary skills and give 100% for things that you love and make you money. The people at the far end of the learning curve demand a high value because of their rarity