My wife recently ticked me off for not replying to her sms.
She sent me a message on the phone a couple of hours before and later in the evening, she complained that I did not reply her sms.
She added, "What can be more important than replying your wife's sms?".
So I nonchalantly replied, "Nothing is more important than replying to your sms".
In actual fact, I was doing 'nothing' at that time and since 'Nothing' was more important than replying her sms, I continued doing nothing instead of replying.
Doing 'nothing' is actually quite useful and relevant in context, since nothing is always more important than something.