Early years guilt
I used to have guilt about masturbation during teen-age years. Girl friend and I shared our individual nightime experiences (we never watched each other). We shared them on the way to work, and at times said we would try NOT to mastubate for several days. This rarely worked! Seems either or both of us succumed to the thrill! I have no idea now why we felt we should abstain, guess at the time we thought it injurious to our health? And we never shared how we did it, or how many times that night! Or maybe felt 'good girls' did not do it! Odd we shared, as I was very self concious about it, and tried to hold actual cum (obviously that did not work, no more than guys holding their penises I guess!)
However, since then I don't remember guilt, though at times think I maybe do it too often (about once very two days on yearly average.) But the pleasure is soooo good I won't give it up! In fact as soon as I turn my light out, my hand goes to my pussy (usually I fall asleep before I even start) When I was married I did it when hubby was out- or asleep. I always have got stronger orgasms masturbating than intercourse, though have to admit I do like the feel of a guy in me! But at my age guilt is long gone, I am now happy I can still orgasm without too much effort (I have to admit there are days when it seems I won't get there.)
No idea why there is guilt, guess some non-unsubstantiated thoughts it is harmful to health? Only problem I get is some rare days when I want two or more, so I lose sleep! Otherwise, I am a healthy 60 year old woman!