Stercus accidit - Shit happens
Stet - Let it stand
Struit insidias lacrimis cum femina plorat - When a woman weeps, she is setting traps with her tears. (Dionysius Cato)

Studium discendi voluntate quae cogi non potest constat

Study depends on the good will of the student, a quality which cannot be secured by compulsion

Stultior stulto fuisti, qui tabellis crederes! - Idiot of idiots, to trust what is written!
Stultorum calami carbones moenia chartae - Chalk is the pen of fools, walls (their) paper No Graffiti please. Showing that graffiti is nothing new
Stultorum infinitus est numerus - Infinite is the number of fools. (Bible)
Stultum est timere quod vitare non potes - It is foolish to fear that which you cannot avoid. (Publilius Syrus)
Stultus est sicut stultus facit - Stupid is as stupid does
Sua cuique voluptas - Everyone has his own pleasures