What I think is happening here is that you have not directly in contact with the metal pins or parts of the ESD sensitive components (IC's, transistors etc) on the boards,e.g motherboard,video card,sound card and RAM card.
You may have touched the plastic encapsulated of the sensitive components or the edge of the boards.
That's why you find your components still work fine.
The sensitive components will be damaged by ESD when there is a transfer of static charges from your body into the sensitive components which is encapsulated by the plastic package.
In the future, please follow ESD protection rules.
Your ESD sensitive components may be walking wounded, i.e you may not know when it is going to fail.Most of the times, they would fail when used in the field.