Vim “show my last command” command?

Question

Is there a command which shows what was the last command in normal mode?

Suppose I accidently hit random key and got some unexpected result. Sure I can undo it, but

Answer 1

The text from the last command is stored in the . register. You can see all registers by :display. Unfortunately it doesn't say what the started the normal command.

To see commands from : (command mode) you can use :hist or q: which is limited to the last 20 (by default).

Another ability is to save the undo buffer :wundo undo.bin -- but the undo buffer is binary.

But none of these actually answer your question. I'm curious if it can be done.