If this were true, I wouldn't have had the capacity to even blink or talk by the time I was 16.....
Yes, I concur. I think the only negative to masturbation is if it is done to the point that someone can not engage in sex with their partner due to needing that same level of friction that might not be possible in 'real' sex and if they then also need porn to be involved. That can become a problem.
But what you describe is not true. goodluck
No. If anything, it would help memory, since it is good for the cardiovascular system. All things in moderation.
I've never heard of anything like that....