Tried "training" it. However their algorithm only works in one direction.
If I set brightness to 1 in a very bright room, that's the max level.
If I go in a dim room room and change brightness to 12 as an example, brightness will go up to 18 in a bright room. Training is only in 1 direction.
They have used the same algorithm as an AMOLED phone - super bright in the sun, dim in the darkness. Need the exact opposite for a Kindle. Surprising basic flaw.
When it's bright and sunny, there is no need for a backlight on the Kindle.
However since this is all software - if more people complain, they may actually fix it. Would encourage others who feel the same to send messages to Kindle's twitter page at
https://twitter.com/AmazonKindle