I have fond memories of "Professor Zhang" as I called him. He and Barbara supported me during my gap year after college, when I didn't know what I wanted to do with my career. He hosted me at Danhua events and introduced me to his colleagues, sat down with me in his office to discuss my career (and asked me to prove Fermat's Little Theorem from memory on the whiteboard haha—this was in the context of Bitcoin) and even drove me to/from a high school math tournament while challenging us with physics problems in the car.
The photo that captures Shoucheng for me is one from a Gunn students' dinner at Harvard Junior Parents Weekend in March 2014 at Uno's in Harvard Square.
I just remember him asking us students a bunch of questions, telling stories, making energetic gestures, probably explaining physics and getting slightly red in the face with excitement. I think this is mainly how I'll remember him: being surrounded by young people, sharing with them his joy for learning. I'll really miss that.