zsh !! expands to the last but one command in history instead of the last one

Question

I would expect that !! in zsh should expand to the last command executed. The same as !-1. But in my zsh, it always expands to the last but one.

Example

~$ echo 1
~$ echo 2
~$ !!<tab>

The last !! simply expands to echo 1.

Is there any option that affect this? What should I do to restore it?