An ohnosecond is a surprisingly brief period of time between executing an action and realizing how incredibly stupid or unfortunate that action truly was. It only takes an ohnosecond to hit a "delete" or "send" button and then exclaim, in an indoor or outdoor voice, "Oh no, what have I done?" Almost every computer user has experienced at least one ohnosecond in his or her lifetime. Many ohnoseconds only cause temporary setbacks or minor inconveniences, but a few can have serious repercussions.
One common ohnosecond occurs when sending emails, especially when the subject of the email is derogatory towards an employer or contains other objectionable material. Instead of sending a reply to a specific name on the email chain, a user might hit "reply all," which automatically sends copies of his or her response to every single name associated with the original email. This could include the very last people who need to read the user's strongly worded response. Hitting the wrong button when dealing with forwarded email can be a major ohnosecond situation.
Another ohnosecond often happens when storing important computer files and documents. Instead of clicking on a "save" button, some people may accidentally click on a "delete" button instead, thereby losing what could be the only copy of a very important project. Fortunately many modern computer systems do have safeguards in place which either back up files automatically or allow users to undo the effects of a single error.
Ohnoseconds are not strictly limited to the world of computing, however. Some people have experienced an ohnosecond after closing a locked car door with the keys still in the ignition. Others have made the mistake of leaving a soft drink cup on the roof of a car just before pulling out of a restaurant parking space. Leaving an appliance running or failing to turn off a car's headlights can also create memorable ohnoseconds.
To avoid having too many ohnosecond incidents, computer users should exercise great caution before clicking on commands which have no discernible point of return, such as "delete" and "reply all." Developing a consistent routine for saving important files or ending a workday should also help prevent these kinds of heart stopping events from happening again.