(TL,DR at the bottom) Guys here talk about their insecurities and ask about size but we never talk about where the insecurity comes from. Men are constantly told "it's in your head" and "men care more than women" but it's not that simple. Here are my thoughts on where the insecurities come from and I think there is more than meets the eye

1) The rise of social media: Twitter and TikTok etc. are very far reaching, and one comment by a woman leads to comments, likes, reposts, retweets, response videos, everything. This is ever increasing and different than previous generations (like mine-- I'm 45 years old). This is primarily women doing this.

2) The thought that "Bigger Is Better": This is mainly specific to the US-- big trucks, huge fast food meals.. we want things to be big, fast, and we want it NOW. I think that attitude spills over to penis size, even if it is subconsciously. Both sexes are guilty.

3) The easy availability of hardcore porn: When I was a teenager you were a lucky kid if you stumbled across a Playboy or Penthouse or a VHS tape. Now porn is widely available online, and available to children. The porn is harder than it used to be and there is so much of it. It leaves an impression at a very young age. Teenage girls now watch porn even if its out of curiosity, and this is ever increasing. This leads to unrealistic expectations. It is not until the women have several partners that they figure it all out regarding the variation in size and what the true average is.

4) Rise of technology: This is shoehorned in with #3. Porn in high definition, better cameras, fisheye lenses, POV porn, virtual porn. I also find it ironic that porn is produced by men and consumed mainly by men. Unrealistic and exaggerated sizes are included in porn by design. There is something about larger sizes that men want to see in their porn. I think with enough viewing it even becomes wired into our brains.

5) Female biology: This is hard to explain, but this is the notion that bigger feels better, especially girth. I guarantee that all of you have overheard women talk about this openly. I have heard it in the breakroom at work in front of mixed company. It doesn't help men any when they literally hear that bigger girth feels better.

6) Lack of education on men's issues and people simply don't read any more: Men simply aren't educated about size. So many studies, and there is not a far enough reach. Sometimes articles do pop up in men's magazines, etc. but consumption of these forms of media are on the decline. It doesn't help that many fathers do not have these discussions with their teenage sons.

7) Third wave feminism and "sex positivity": This is controversial but pertains mostly to women. Woman are now given latitude to talk about sex and size openly, what they like, and previous partners. Sex isn't taboo anymore and women talk about it openly and it becomes and echochamber.

8) "Men put pressure on themselves": I put this at the bottom because I think it is relatively minor. I need to be careful here so I am not accused of misogyny, but to be completely honest I think it is deflection by women. It is blaming men for their insecurities when the women had a hand in creating them. I think that notion of "size isn't everything" and "motion of the ocean" is simply virtue signaling by women in many cases. When men do put pressure on themselves, it is certainly amplified by forums such as this.

Wow, this became a huge wall of text, hopefully it leads to a good discussion

TL, DR: Penis size insecurity comes from a variety of sources, including the rise of social media, the thought that "Bigger Is Better", easy availability of hardcore porn, rise of technology, female biology, lack of education of men's issues, 3rd wave feminism and the sex positivity movement, and to a lesser extent pressure men put on themselves.