Synchronicity has been covered here before, and rather than start off by rehashing it again; I will simply give an example of it from my own life just yesterday.
In the morning I walked out front to bring in one of the recycling/disposal bins. I noticed a piece of paper laying along the side of the property. As I was picking it up, I noticed that it was a label from a San Pellegrino bottle. I immediately thought of "synchronicity" being that S. Pellegrino water is from the Alps of the Bergamo province in Lombardy. After pondering that possibility for about three seconds, I concluded that it was more likely just coincidence.
About an hour later, I took a break by walking to the back of the property where there is a deck next to a few trees overlooking the side of the lower mountain slope that it rests upon, as well as the bay in the distance. The book that I am currently reading is 'The Book of the Holy Strega' by Raven Grimassi (2012 edition). The book explores the legend of a woman in fourteenth century Tuscany named Aradia (pronounced "ah-RAY-dee-ah"), who led a group of followers across the countryside teaching people about "the old religion" (the native magical earth-based heathenry aka "witchcraft"; which I prefer to call "witcheathenry"). After a few moments of sitting and reading, I came to the following text: "And the fame of her wisdom and beauty went forth over the land, and the people worshipped her, calling her La Bella Pellegrina."
At that moment, I knew that the "coincidence" of an hour earlier was actually "synchronicity." San Pellegrino means "Saint Pilgrim" in Italian, in masculine form; while San Pellegrina is the feminine form. It doesn't come any clearer than that; yet impossible to literally prove; except in your mind you can gauge the odds of this type of connection happening over and over. Reading a book regarding a subject of some importance to you is the best way that I know of to invoke these types of experiences. It either happens out of the blue, or you can consciously will it to happen (not force it). It's important to note--and even highly intelligent people have made this error--that these connections do not make you special or "the chosen one," but it's more like an affirmation of the universe telling you "good, you're on the right track." Have fun with it and read all of the messages and symbolism around you, while your driving or walking. Three black birds or three ravens are a big one with me, and that ties into Norse, Celtic, and Alpine mythology... as well as my own family coat-of-arms. Also, the number 18, silver (more often as a word), iron, the letter "C" (sometimes "B" as well), and a body of water on or next to a mountain... just to name a few off-hand.
Having the masculine "pellegrino" message seemingly "delivered" to me next to the morning paper; and soon thereafter reading about Aradia the "pellegrina," reflected deep personal synchronicity, and even for reasons that I cannot divulge at this time. Also, the landscape from the deck closely matches the landscape from the cover of the book! All of this doesn't mean that I'm special in particular, but only that I am on the right track. One's actions will ultimately determine how "special" one may be. Are synchronistic messages and symbols the way that our goddesses, gods, god, angels, or spirit guides communicate with us?
Three days ago, while running an errand during twilight, I was driving down a street with a mild amount of traffic. It was the type of semi-major street that cuts through a bedroom community. Someone was pulling out of their driveway, and I slowed down. Just a few seconds before I was about to step on the a gas to get going again, I noticed a woman standing on the sidewalk looking at me. We made direct eye contact, rather than a simple glance. Her eyes were almost hypnotic as she looked into my eyes along the dimly lit street. I wanted to keep looking at her for some unknown reason, but I turned away after three to four seconds. She never looked away. I don't know that it would make sense to describe her in any detail, but suffice to say that this could have been a message of some type. People or animal messengers merely "act out" the message unknowingly; and we have all been a messenger for others unknowingly. Ultimately, we as individuals must decide what these messages--if we choose to seek them--might actually mean.
That woman really presented me with a strong (non-sexual) message, which I think I may understand; but this subject is bigger than any one person, and I'm merely trying to give some examples of it for others here. The individual needs to develop their own set of codes, numbers, letters, words, people, animals, incects, landscapes, and symbols. For me, a white-furred animal or insect represent a certain positive energy. Those little white butterflies symbolize that for me, and I call them "angels of the day." Sometimes very fair people can fit that symbolism, but usually in the form of a small-statured woman. White cats also have a certain positive energy to them. I once knew a female white-furred dwarf cat who everyone thought was so docile, but she would stare down big dogs who ran at her. She couldn't even hear them because she was deaf, and thus wouldn't even flinch; but the dogs always backed off because she wasn't afraid of them, or sometimes because she took a swipe at'em! She was sort've like an "angel of the day," standing firm against negative or potentially harmful forces.