From somewhere on the web:
Whenever you're going sailing, regardless of whether you're racing or just going cruising, a great amount of preparation has gone into it. Your boat needs constant care and maintenance, you need to buy supplies and see that everything is in shipshape. In that context, there's the typical satisfaction in getting a job well done. When you're finally done with that and head underway, there's the anticipation of adventure, at least the possibility of one.
When you're done with the preparations, you leave the harbor and hoist up the sails. You turn off the noisy, vibrating engine, after which there's no sound except for the wailing of the wind and the sound of the sea. I always start smiling at that point. The boat speeds up, starts to list and everything comes to life. At that point, the boat doesn't feel like a clump of glass fiber or wood with lines, metal wires, and sailcloth stacked on top of it, but instead like something truly alive and with a personality of its own. Sometimes it's is in a good mood, providing a laid-back experience, whereas sometimes it feels more excited and slightly frightening, going up to the point where it feels like you're trying to rein in a blood-crazed stallion on some really bad acid.
You're constantly barraged by an abundance of information, from wave shapes and currents, wind vectors and sail trim, to the feel of the rudder and helm and keeping the boat on the desired course, along with a myriad of other variables. All of these things change constantly, and you learn to internalize them to the point where reacting to them isn't a conscious process. It would be impossible to react to them otherwise, as there are literally thousands of variables at play and going through them logically is too time consuming; by the time you've gone through any check-list, the conditions will have changed again. Instead, things might just somehow feel or look a bit wrong, and oftentimes you react to such stimuli without even thinking. When you manage to hit that sweet spot, where everything just aligns perfectly, you feel a strong sense of elation. At it's best, it's like being in a constant flow-state of mind, where you lose your sense of self, and the lines between you, the boat and the prevailing elements get blurred. You feel connected to something outside yourself, namely the boat and the sea, both of which have their own will. At that point of realization, you stop wondering why sailors throughout the ages have anthropomorphized both boats and the sea.
When you're on the water, you have an unbridled sense of freedom and opportunity, as you can always continue to see what lies on the other side of the horizon. Not only do you feel a strong connection to the elements and nature, but to the entire world. I suppose one could say that about walking in the forest as well, but it just isn't the same, as practically every time you're out sailing, someone suggests (mostly in jest) that "you do realize that we could just point the bow ten degrees westwards and continue on to the other side of the Atlantic" or something equivalent. That sense of freedom just doesn't exist on land.
In addition to all of that, somewhat oxymoronically you feel isolated from everything else. The rules and routines of everyday life just don't apply in the same way anymore. One example of this is that as most vessels are small enough to be called cramped, you're in constant contact with the other people on board. You learn to know those people well, as being on a boat will inevitably reveal the true nature of your shipmates. I've seen fights erupt due to absolutely trivial matters, but more often than that, I've seen everlasting friendships forged through working together in order to fulfill a common purpose. If you sail long enough with someone, you internalize their thought-processes as well, to the point of almost being able to having a telepathic link. The only time I've experienced something similar is while playing music with other people.
All in all, to me, it's about being removed from a mundane environment, feeling fully mentally connected with something else, be it the sea, the boat or the crew, with a constant state of shared Flow going on and realizing that everything stated above can take you most of the way to anywhere on this planet of ours.