RobH_en_tn/2th/02/05.md

Do you not remember ... these things?

Paul uses a rhetorical question to remind them of his teaching when he was with them previously. This can be expressed as a statement. Alternate translation: "I am sure you remember ... these things." (See: rc://en/ta/man/translate/figs-rquestion)

these things

This refers to the return of Jesus, the day of the Lord, and the man of lawlessness.