Cuckolds, like me, are people. There are no simple, easy, universal answers. We are individuals. I think one fairly common thread in the experience of cuckolds is that we have had many things happen to us in life that undermined our self esteem, our confidence, our feeling of manliness. I also think a good percentage of us happen not to be well endowed physically, which is probably at the root of our life's history of having our self esteem and confidence undermined. Yet we aspire to what everyone else does...a beautiful, desireable, loving girlfriend and, eventually, wife. Gradually, after many disappointments, we begin to "settle"...for some, that means settling for less than the ideal wife, who may be no more attractive or successful in dating than we are; for some, like me and many others, it means settling for a relationship (sometimes including marriage) with an a-list woman who is interested in us for reasons other than the normal male-female attraction reasons. We accept a realtionship with one of these desireable women, even while understanding that they are willing to be with us for reasons other than physical or emotional attraction...and usually those reasons are a secure and comfortable lifetstyle, with few demands, with her in control. Once that is your mindset, and once you cross that terrible but incredible line that you yield your marital sexual rights to better men, in your intense desire not to lose your "prize," you become a cuckold and gradulally adjust to your position. From there are a whole bunch of possible scenarios, but for some of us, the path we end up on is that of submissive cuckoldry.
Don't know if that helps, but the main point is there are a lot of us, and we have ended up here in a lot of different ways. But it's all rooted in physical and psychological weaknesses and inadequacies, that work out into a cuckold lifestyle.