SICP takes _ages_. I'm working through it myself but have realised it's going to be a background project for the next year or so. No idea how MIT freshman do it so quickly!
Indeed. SICP does take ages. I only worked through the first three chapters and it took me a year. I skipped a handful of problems that simply didn't interest me enough. This was several years ago and I hope to pick up from where I left off some day :/
I figured that they don't have to work on most of the exercises. If you want to do that it will take forever. I'd say if I want to try it I'll just work on lab projects and just a few exercises just to warm up and stop whenever the problem is too difficult for me.