It's more about taking an analogy where you compare a normal distribution to something that isn't a normal distribution.

Physical capabilities of organisms (e.g., strength, speed, jumping height, etc.) tend to fall into normal distributions.

Knowledge work where you can take advantage of powerful (mental | software) abstractions don't tend to fall into normal distributions, as previous work can make a bottleneck disappear, leaving you with more mental bandwidth for other concerns, which quickly expands your capabilities.