I don't have experience with external factors, but I can assure you that the feeling of failure etc when it's down to your own choices, seems much more acute than if you had a valid excuse.
Both are painful. When I'm struggling, is it better to know that I justly deserve it as a consequence of my own choices, or that fate has capriciously inflicted those struggles on me? Whichever situation I find myself in, I'd rather be in the other one.
