Unfortunately, i know enough to be able to say, that i have obsessive traits. What is commonly known as "OCD" by those who don't know what OCD really is. The psyche of all people, is composed of a mix of neurotic traits. They are like different forces fighting each other, pointing to different directions. When one such force is so powerful, as to dominate the others and to drag psyche to its direction, it then become "neurosis". Fortunately, most people are unaware that they all also have neurotic traits and are only able to see them in others, because they are weird to them, being their own the "normality". For example, a housewife that likes order, irons the clothes, bends them neatly and puts them in the shelf and pats them down to look tidy, has likely obsessive traits. For a housewife that keeps her house like a bombarded field, the first one has OCD, while she is normal. It becomes OCD, when it becomes a standard, repetitive, ritualistic behaviour, where the individual finds comfort in doing it, even for no apparent reason.
Or, to put it with an easy television example. You have present the meticulous detective doing CSI work, looking at the last place someone would look and finding a clue? If you have obsessive traits, you will excel in that job, because you pay attention to things that others may not. Fast forward to the detective "Mr. Monk". That's OCD. Because it's obsessive trait gone "rogue" (aka neurosis).