My first prostate exam happened when I was in my 40's. I would say I certainly felt it, kind of like a shockwave sent through my entire body when the doctor pressed on it, and then it was over within a second or two.
Being anal erotic before I knew what being anal erotic was (pre-puberty), I didn't really begin to explore my prostate until well into my late 40s and that was from doing my own research during the early days of the Internet.
I did not connect my anal erotic physical feelings with my prostate when I gave myself enemas at age 13 and how it contributed to my pleasure. It wasn't till my 40's when I started to stimulate it directly with prostate toys when they hit the market. Learning about prostate pleasure was like discovering King Tuts tomb of treasures- it opened up a whole new world of anal pleasure.
I would hope now that young boys who are handed a smart phone when they turn 3 years old and learn very quickly that it is a window to the world (for better or worse) and discover how their prostate plays an important role in sexual pleasure. They may keep it private or discuss it with their friends. Some will pursue their curiosity and learn how to unlock this pleasure center.
My first few digital prostate exams showed me it was a super sensitive gland- the exams did not produce pleasure. But as the years passed and I was becoming very a tunned to my prostate and when stimulated with light pressure or stroking or vibration it produced great pleasure.
I will say not all guys do derive pleasure from prostate stimulation. I performed a prostate massage on a guy who was all top- his first prostate massage and he just did not get much out of it. A mental block maybe occurs when a guy is very focused on being the penetrator vs. being penetrated.
So, to really enjoy prostate pleasure I would say you have to be totally open to it and willing to try it. If you do, you just might hit it big like discovering King Tuts tomb.