As you read more, you'll discover that a lot of us started crossdressing very early in life, for whatever reason. As we continue to do it, the behavior of feeling as if we either are a girl or are supposed to be a girl eventually becomes part of our personality during a vulnerable period of development. And once you've reached puberty, it's permanent; there's no known way to remove it. The nearest comparison I can give you is this: It's well known that when children learn a language at an early age, they will be able to speak it without an accent from their first language. But if you learn a new language after puberty, you WILL have an accent in any languages you learn afterward. This is because the part of our brains associated with speaking and language 'finalize', if you will, and it becomes permanent at about the same age as puberty, perhaps influenced by the same chemistry changes in us that cause the secondary sexual characteristics to take place. In much the same way, I believe (based on everything we know about sexual identity) that our self identification becomes permanent, and for us, it leaves a permanent feeling of wanting to either dress, dress and behave, or even BE female. There is no exact science in this; gender identity studies are still in their infancy, and very very few therapists know anything about it. All the rest of us have to go on, is our own experiences and our discussions with others who share similar gender identity 'distortions'. And not all of us are competitive in crossdressing, either. I believe that a lot of the picture threads you refer to are simply guys who desparately want reinforcing feedback that tells them that they pass, that they could be a beautiful female should they want to become one.
Also please remember the tremendous sense of guilt virtually every male is imprinted with throughout our entire lives, that to be anything feminine it the worst possible thing we can be, and if we dare to do it or even worse, enjoy and embrace it, then we are the lowest of the low, the worst examples of what humans can be. After all, much of society detests us, finds us repulsive, want us banished away from their children lest they become 'infected' with the transgender thoughts. And it leaves perhaps 95% of us without any love or affection from anyone at all; and that's a killer. We can do without sex, at least with other people. Basic sexual urges and needs can be satisfied by masturbation; but the need for physical affection cannot be fulfilled alone; you can't give yourself a hug, you can't cry on your own shoulder when you're sad, you can't comfort yourself when someone you know dies. The stress of all this, of course, eventually wears us down, making us more susceptible to infections disease, autoimmune disorders, high blood pressure, all sorts of health problems. The worst are the addictions, the desparate attempts at coping mechanisms when all else has failed; alcoholism, drug addiction, eating disorders (that's mine, more on that later).
A lot of us subconsciously suppress the desire, even the thoughts about crossdressing, nearly 100% of the time. Consider when you're physically hungry; sure, you can hold off, even though your stomach is growling for something. But it's constantly there, reminding you that it's empty, and the more you ignore it, the stronger the signals that it's empty become, sometimes even to the point of pain, and at some point you simply cannot ignore it anymore. Crossdressing is the same way, just in the brain. And of course, over the years, it all builds up, sometimes eventually 'exploding' when we can't hold it back anymore. Let's face it, a great percentage of us really believe in miracles, and believe that if we keep praying, eventually god will hear us and help us. As life goes on, it becomes clear that it's never going to happen. So we start to take things into our own hands, sometimes even to the point of fully transitioning and sexual reassignment surgery. And for those, the positive reinforcement about how much we can be accepted as a female is critical. So for that I truly wish you don't be too downtrotten on the guys who want to be told how pretty they are and how well they pass. A lot of us realize that it's not true, it just feels nice to be told it, and here, getting a message from someone with a female name, with an avatar of an at least somewhat passable mtf, we can sort of believe for a while that REAL GG's will accept us that way, too.. What I don't understand is how it becomes THAT much bigger when you're older, growing from a simple, regular enjoyment of women's clothing to the point where you're using a female name, outing yourself to family and shopping at Walmart in a wig.
I hope this helps answer your questions. For more insight, click on the link to my bio in which you'll discover how a normal boy can become TS, or at least believe he is, and by believing that through childhood years it becomes a permanent part of who he is.