It's the main cognitive functions of being ISTJ (mbti personality type)
Si (introverted sensing) - used to compare present experiences with that of your past memories resulting in deep internal awareness, subjective physical sensations, and strong personal traditions
Te (extroverted thinking) - focused on logic, objective data, efficiency, and structured outcomes. People with strong Te are highly action-oriented, preferring to organize their external environment, establish standard operating procedures, and execute tasks directly to reach their goals
(aka our little cute baby sangwoo chu )

sangwoo is so SiTe coded that he literally can't function if his plans don't go accordingly to what je wants to achieve