Lightroom has, in my opinion, a lot of 'hidden features' and I recently discovered some of them:
- First are the entry helpers in the Library Module. If you click on a label a menu appears with the last entries.

- Second feature is to reset a specific development setting in the Develop Module, like Brightness. Most of the times I used to double click on the handle of the slider. But it's a bit fiddling around. It's easier to double click on the label (e.g. Brightness) and the slider will reset to the default setting.