I do not mean this as empty snark; it is something you can see across the board in programming language evolution. It is virtually impossible to propose a new general-purpose programming language today that does not have closure support, which is the biggest thing you're finding missing from C and Java to use the techniques in SICP. (It is not the only thing, but it is the biggest thing.) You'll note Java is going to bolt them on soon, or recently bolted them on, but it'll be another decade before Java is using them fluently either way.

I've often recommend SICP to self-taught programmers; it is not a complete substitute for a computer science education, but it is a concentrated dose of the stuff you're probably missing out on. Expect it to be the work of some months to work through it. However, in the end, a self-taught programmer who has also worked through SICP systematically and carefully is probably a better programmer than 80% of the modern computer science graduates nowadays. (If you want to avoid that fate, oh ye who are still in school, take the freaking compilers course at the very least. Do your peers complain that it is hard? Then maybe it is a good one.)