Why keyboard navigation in Google search results didn't work for me in years

For many years, it had been bothering me that keyboard navigation in Google search results had seemingly stopped working for Firefox. That is, using tab, arrow keys and enter to select and navigate to result entries. Judging from a recent HN comments thread, I was not the only one experiencing this, apparently.

Just today I happened to see my girlfriend using arrow keys navigating through results in Firefox and started investigating again. As it turns out everything works as expected in a private tab, so I figured it has to be related to my search settings. After some fiddling with them, I came to two somewhat weird conclusions:

- Keyboard navigation is coupled to Google Instant, i.e. will only work if that's enabled

- Google Instant was completely disabled in my settings

This is kinda weird because I cannot remember disabling that, nor am able to understand why keyboard navigation shouldn't be possible without instant results. Are there maybe some Googlers around here who have insights on why this is?

Anyway, re-enabling that feature ("if my computer is fast enough") brought back keyboard shortcuts, so I thought I'd share and it might help someone else as well.

TL;DR: If Google search keyboard shortcuts don't work for you, go to Settings > Search Settings and enable Google Instant.