On OpenBSD, Gtk applications use Emacs key bindings by default. I find this frustrating, as I expect C-a to select the entire text.

To revert to the default key theme, I needed to modify some configuration files.

For Gtk 2, include the following in ~/.gtkrc-2.0:

gtk-key-theme-name = "Default"

For Gtk 3, make the following edit in ~/.config/gtk-3.0/settings.ini:

[Settings]
gtk-key-theme-name = Default

Now it feels better.