Heath Ledger didn't just prepare for a role. He dismantled himself to build someone else. A month alone. No audience. No approval. Just a notebook and a descent into chaos. Most actors would have played it safe after Jack Nicholson's iconic take. Ledger went in the opposite direction entirely. Michael Caine. 60 years in the industry. Forgot his lines on sight. That's not acting. That's obsession weaponised into art. He never saw the Oscar. But the performance outlived everything.