Since ending any engagement with pornography and masturbation, one of the most noticeable changes I have experienced is a build up of emotional energy, which can be channeled into various creative endeavors.
It seems that the practice of semen retention is a gateway to allowing the body's energies to naturally flow and expand, which encourages better quality of life and more creative potential. Various resources explain this by saying it allows Chi/Qi/Prana to move past the first couple of energy centers (chakras) and energize higher ones, such as the solar plexus, heart, throat, and mind's eye. When this happens, more human potential is activated and thus various benefits result. Because of our intense yearning for sexual connection and the prevalence of the internet, though, there is a tendency to get caught in behaviors that prevent this natural expansion from happening.
Another aspect is that semen contains valuable minerals and other nutrients (such as phosphorous and zinc), which can be reabsorbed into the body if semen is conserved rather than released. This fuels the organs- such as the brain- and helps the body function better. If the body has enough essential nutrients, it means that it won't be in a state of deficiency and the individual will experience a better quality of life for it.
In terms of specific personal benefits, the heightened physical and emotional awareness has translated to a better ability to focus while reading and writing, doing artistic projects, and exercising (among other things). I can plan my day better, come up with better ideas, and follow through on things better without feeling as sluggish as time goes on. And this is not just about my personal story... many guys (including famous athletes and intellectuals like Muhammed Ali and Nikola Tesla) have espoused being more consious about their sexual energies as integral to their success and growth.
Much information I've shared here I got from a book called "The Semen Retention Miracle" by Joseph Peterson- which goes all over the map to explain semen retention as an ancient practice rooted in spiritual traditions and as a modern movement towards helping men access more of their potential.
If it seems interesting, there is no reason not to give this a try and see how it can help you overcome challenges and live a better life!