Mastery is not that hard to understand. It is to become a better man. A more valuable man. Changing yourself to a better one.
When I was a teenager, as was crazy about a blond girl. She was really so beautiful! She was that angelical type, green eyes, skinny and beauty. I dream to me. (She had, also, a twin sister). So, there was a situation whem I could go out with her and some other friends (I took my dad's car to take them at home), and tried everything I know that time to be with her. But I was DUMPED, and I saw her kissing other guy in the front of my eyes. That hurted a lot...
This example is no different of what happened to a lot of guys here. But take a look what happened next. I do NOT stayed the same.
I kept my training on the gym 5 days a week, and got my body better. I got a nice paying job, so I could finance a house and buy a nice car. I turned my house into a nice place to be, with stereo, video, and always with things to eat or cook and drink (beer, wine, vodka, whisky, tequila, etc...). I could buy cool outfits. I could sometimes pay a good place to have a dinner or a good party. I became a better man day by day. And, at that time, I didn't know nothing about the manosphere.
Some years have passed and... what happened, in a nutshell? I got that blond girl I always dreamed of, to the envy of many. I stayed with her for about a year. Her twin sister had come with us for some fun in my house sometimes, and... in the end, I had a mannage ménage à trois with her and her twin sister. After some months I dumped both for better stuff ahead.
My example shows that you CAN better yourself, and have better results. Some changes can be made today, but some can take some years to take effect. The fact is that you must, like pook said, unite day and dream. This means that, the man you want to be need to be constructed day by day. Wanna a better body? Go to the gym. Wanna a better job? Go for it, study. Wanna have your own businnes? Make it happen, study the field you want to work in, etc...
Today I'm a guy that - very different from my teenager time - have options, have girls to choose. Why? Because, now, girls want to be with me, c'os now I'm a nice catch. There are girls that have more hadsome guys than me to be with, but they choose me. Why? Because I don't stayed the same, I'm always changing ant trying to be a better man. Reading, studing, working out... always. Girls are not dumb. They know the guy that can give them more. That's why the choose me, that's why I have options. I just turned myself into a nice catch.
This do not mean that I can have all the girls I want. Far from that. But you know what? I don't care when I got dumped today, c'os I have my plates to spin, I never sleep alone (except when I want).
I also want to say to the newcomer DJ's that a hot girl is not all. I had been with 8, 9 HB, and, besides their beauty, they are NOT perfect girls. They are normal people, and have flaws and things that you do NOT want in a LTR. In a nutshell: do not choose a girl just because she's hot. To have some sex it's ok, but if you wanna a good LTR, be more picky. Do not be in a bad relationship just because she's hot.
The real thing you must fight against is your own mediocrity and laziness.
If you are in the path of self improovement, don't care about the others say. Just keep it up. Results will come. Endure!!!