kiss over 10 seconds was a mortal sin....1961....so....you learned to breathe on 10.....
No, some nun made the prudential judgment that a kiss over ten seconds must have an erotic purpose, and therefore be mortal sin. The notion that breathing every tenth second somehow made a distinction between mortal sin and spiritually healthy is, was, and always has been absurd.
49 years later a 10 second kiss could simply be fatal. Ah to be young again!