Console on 10.2.5 not showing history before Console.app started I know that I used to be able to start up Console to see things like what happened due to a system error: you could just fire it up and search for the most recent "boot" and look at the events before that to see what had happened.

Now, however, it seems that my scrollback in Console.app is limited to the moment I started it. That is, I would have to have it running all the time in order to see what's going on on the system, and what I described above (i.e., seeing what's going on around a boot/reboot) is impossible.

Is this now the new behaviour? I admit I hadn't looked at it for a while (probably an OS version or two).

I should mention that I had to restore my machine recently from a Time Machine backup. That's the only notable variable I can think of.
Ah, as Phong notes, this is a duplicate of Sierra Console.app show earlier data.

The short version is that the Sierra Console.app behaves this way currently by design (although there are a couple of workarounds noted in the other answer, depending on what you want).