> knowing everything there is to know about sex without actually practicing it is not the same as having sex.
Your premise only seems plausible as you state it because you are not actually considering the implications of knowing everything there is to know about sex. But knowing everything there is to know about sex includes knowing what it is like to have sex. So the real premise you should be stating is that it is not possible to know everything there is to know about sex if you have not actually had sex.
And, as you appear to realize, making the appropriate adjustment in how the premise of Jackson's Mary thought experiment is interpreted makes it obvious that the argument is invalid--and I agree that it is.
Your premise only seems plausible as you state it because you are not actually considering the implications of knowing everything there is to know about sex. But knowing everything there is to know about sex includes knowing what it is like to have sex. So the real premise you should be stating is that it is not possible to know everything there is to know about sex if you have not actually had sex.
And, as you appear to realize, making the appropriate adjustment in how the premise of Jackson's Mary thought experiment is interpreted makes it obvious that the argument is invalid--and I agree that it is.