Why do some people seem to attract calamities and obstacles of varying sizes, and others don't?
That's a very deeply metaphysically question that deserves a deeply metaphysical answer. The short answer is, they attract the misfortunes by the way they look at life; their perspective or viewpoint. There are several ways in which this can happen.
The perspective I chose to explain, I personally use. And it works very effectively:
Letters on a page appear backwards in a mirror — your environment is a mirror. But if you have a second mirror in which you look at the other mirror's reflection, the letters appear in the correct way; they are no longer backwards. When the environment is backwards, there is a continual series of mishaps. To have the environment reflect your intent accurately, you need a second mirror.
The way I create a second mirror not only manifests my intent accurately, but manifests it even more abundantly than can be foreseen. An image of yourself in a mirror multiplies into many images when these two mirrors are placed one behind you (depicting the past) and one in front of you depicting the present.
The perspective to cultivate of the present:
When you realize that, because life is an ever-flowing river of events, even the present moment cannot reveal the true nature of what you experience or see. By the time you see it, it has already changed. This is one of the reasons life is unknowable. (The other is that from our limited and contracted vantage point, we cannot see the bigger picture.) How then should we approach life in the moment? With the wonder and awe of realizing with the utmost humility that we are looking into the heart of the unknowable.
The perspective to cultivate when looking at the mirror of your past (this perspective of the past creates the second mirror that reflects your intent accurately):
The past immediately changes with every experience and choice you make in the present moment. It is a fluid response to life in the moment. Thus the past is also unknowable because we can't see what it has become, and to think we know what the past is like, is folly.
How then should we see the past? Acknowledge that it too is unknowably changing moment by moment beyond what the mind can grasp.
Because the past and present are inextricably intertwined, mutually shaping and entraining each other, experience the moment's gifts with gratitude, fully aware that the blessings of today had their origins in yesterdays gone by. Do not hold on to the illusion that you can know or remember your past. To do so blocks the potential of glad expectations yet to be fulfilled, and distorts the second mirror's accurate manifestation of your intent.