I'd differentiate between the "f8 and be there" mode of photojournalism and the serendipity of other types of photography - say street or fashion.(posted 8549 days ago)The demanding conditions of many kinds of photojournalism put a premium on getting any image at all. Since it is rare to have the opportunity to exercise much creative control over the result, the photojournalist is as much valorized for his/her bravery, ingenuity, and persistence as for anything else.
At the other end of the spectrum, your journeyman wedding, fashion, or portrait photographer relies almost entirely on technique. Clients come to him for a specific product with a specific look - whether he works for Wal-Mart or is doing a full-page ad for Vogue.
But at some time we all hope to get the opportunity to be more creative. That's when technique and circumstance come together to give us something that we didn't (couldn't) have totally foreseen. When I did that shot of Vick, I knew the basic parameters of what I wanted - a b/w headshot that could be cropped square - hopefully down the center. However, the final result, including the angle I chose, the background he chose, and the light (that was unadulterated) was as much due to serendipity as plan. And I think that that little thrill you get when you first see your contacts (or an initial Polaroid) is a big part of why I like photography.
In short, "Serendipity Happens."