Like many health issues (mental or otherwise), its a matter of degree.

Everyone can relate to the experience of lacking the focus to perform an un-stimulating task, and to the experience of procrastination - and so that often leads to the kind of blasé reaction you offer here (no offense). This is a very harmful kind of attitude.

Everyone can relate to the feeling of being sad too - that doesn't mean we're all suffering from depression. Most people can relate to the experience of drinking too much. But they aren't all alcoholics.

It's when the degree of such behaviors/states-of-mind become so prevalent and unshakable as to be destructive and harmful in a person's life, that they become disorders.