Acute insomnia can last just a few days or be a problem that comes and goes over time. It is caused by stress, pain or discomfort, another medical issue, environmental factors, or a change in your sleep cycle.
Chronic insomnia is long lasting and more severe.
You do not have insomnia if you stay up all night by choice.
You do not have insomnia if you spend the entire night on the internet just because you can.
You do not have insomnia if you wake up tired to your alarm after only four hours of sleep.
Tips for dealing with insomnia:
Ultimately, it's something you have to work at each and every day. You can't just fix things overnight and drugs aren't the best option either. You may not even have chronic insomnia to begin with and it may be related to stress or some illness, in which case, you need to deal with that first before you can get decent sleep again.
One more thing, you may not need as much sleep as others do anyway. If you can wake up feeling rested after only five or six hours of sleep, there is nothing wrong with you. Enjoy your extra hours, by all means. Just because you are awake at 2 AM does not mean you are an insomniac. It's when you lay in bed for hours at a time and can't sleep or wake up constantly in the night or feel lethargic and irritable all day long that you have to worry.
And, from the insomniac's point of view, just saying you are an insomniac when really all you are doing is forcing yourself to stay up to watch a tv show or something on youtube? Yeah, we don't like that. And you're not doing yourself any favours either.