First of all, beware of diagnostic labels. Certain labels gain popularity, and all of the sudden everyone you know has the same one.
True obsessive-compulsive disorder means you cannot function normally. This is true for any actual mental disorder. In order for a person to be truly mentally ill, their illness MUST interfere with normal, everyday functioning.
I think that a lot of people who have been told they have OCD or have decided themselves that they have it do not actually have a mental disorder. They are just irritated by messes, or need to have things a certain way, or ruminate in their minds over certain things. It can be a relief to put on a label, because then you have an easy way to talk about your issues and you can get treatment for the problem. But it can be a kind of mental laziness, as well. It's less challenging to say "I have OCD" than to deal with your control issues and accept that you need to change.
All that said, some people DO have OCD. Here is a link to a page with the official psychiatric definition:
If you find that your thoughts are unmanageable and interfere with your ability to function, and/or you are compelled to perform tasks that many people would find useless or weird, you may have OCD. If this is the case, see a doctor.