I think my own skills are way beyond most people's because I've imagined it so much and built it up as an idealistic thing, but a lot of it is stuck as potential because I have so seldom and few times actually had the opportunity to act on my great imagination. I think it has a lot to do with believing that giving pleasure and receiving pleasure are equally enjoyable and gratifying and fun and what you want to do. The magic of the big penis (and I guess in addition to being big it also has to be a very beautiful and good tasting and good feeling and attached to a compatible person with complementary erotic frameworks and ideas and desires) is that it feels to me like BOTH the sucker and the suckee are feeling like they are getting that ideal mutual giving and receiving. I know some people are able to feel like they are receiving pleasure from sucking a small or average penis but for those who enter the mythology that supports the idea that bigger is better, sucking a large (and above-described) penis is so rewarding it changes the dynamic of giving/receiving. Part of what makes it seem exciting to me is that you can feel like you don't even need your own dick sucked or paid any attention to while you put all your attention on the bigger dick. That defies intuitive and logical assumptions. It's like, "OMG! This cock is so awesome all I want to do is show him how great it is!" and while doing that you enjoy the sensations, the sight of it, the feel of it, the differences between your cock and his, etc., that you can get lost in what seems like totally giving, but you end up receiving very mutually at the same time. The few times I actually got to go down on a well hung partner I was beyond great at doing it. Unfortunately, when they were thinking they had to reciprocate, it interfered and cut me off and I couldn't treat them to the best BJs they ever had or would ever have which I was capable of. A big part of what makes you "good" at it is whether you both share the same expectations of what you want to do, how you want to move together, etc.