You can tell if you have OCD (Obsessive Compulsive disorder, when you realize that you forget so fast about something you have done immediately. For example, a victim may check and recheck again their door handles severally to see if they have locked them before they go. A victim may also grow compulsive behaviors like refusing to touch public door handles. Read http://psychcentral.com/lib/2006/how-do-i-know-if-i-have-obsessive-compulsive-disorder/.
Some of us are disturbed when things are not done s certain way. When the behaviors interfere with functioning normally in society, then its truly OCD. It can be crippling. It can be treated with counseling and medications.