[esafak]

How do you know you're not on a logistic curve?

Don't you think costs and the availability of training data might impose some constraints?

[dragonwriter]

With real world phenomena that have resource constraints anywhere, a good rule of thumb is: if it looks like an exponential curve, walks like an exponential curve, and quacks like an exponential curve, it’s definitely a logistic curve

[HeatrayEnjoyer]

The entire universe is training data.

[esafak]

It is, but we -- humans, and computers -- are limited in our ability to learn from it. We both learn more easily from structured data, like textbooks.