I just finished 'A Clockwork Orange' last week, and the themes are still rattling around in my head. Burgess has this unnerving way of making you complicit. It's not just about free will versus state control, though that's the big one. The language itself, the nadsat, forces you to participate in Alex's world, which makes the question of his 'cure' all the more disturbing. Is stripping away his capacity for violence, and by extension his capacity for choice, actually making him a better person, or just a less dangerous one? The novel suggests the latter, and it's bleak.
There's also a deep, almost cynical look at art and morality. Alex loves Beethoven, and that love is pure and real to him, yet it coexists with his ultraviolence. The state then weaponizes that same music as part of his conditioning. Burgess seems to be asking if art can be moral or immoral in itself, or if its meaning is entirely shaped by the beholder. It’s messy and refuses easy answers, which is probably why it sticks with you.