I haven’t read SICP, but I’ve heard it’s like Let Over Lambda which I have read. Ostensibly, LOL is about how LISPs work, but in reality it’s a much more fundamental look into how execution and scoping do what they do, why, the semantics, etc. I mostly write Python now, but I have a much deeper appreciation and understanding of object orientation from reading LOL. You may find the same with SICP.