Signs, Schmines

I used to believe heavily in signs, foreshadowing and coincidences and that meaning could be derived from such things. I would have a dream about someone I hadn't seen in a while and then see the person the next day. My mom would see a dead mouse on her street in Florida--a highly uncommon sight--and then I would return to my pristine, Upper East Side apartment and find a live one scurrying across my parquet floor. I would be drunkenly thinking about my second cousin who lives in Florida and how she never sent me those damn pictures from a recent family bar mitzvah, and then I would run into her in the 86th Street subway station in NYC while she was passing through town.
Do these things necessarily mean anything; are they supposed to guide me toward a certain conclusion, resolution or along a predetermined path? Probably not, but coincidences are unsettling to me nonetheless, especially in a city as large as New York.