Rule reminder
'Sé' is the reflexive tonic pronoun for the 3rd person (singular and plural). Use 'sé' when the pronoun refers to the SAME person as the subject. Use 'lui/lei/loro' when it refers to a DIFFERENT person. 'Sé' takes an accent to distinguish it from 'se' (if).
Marco parla sempre di ___. Pensa solo a sé stesso.