Understanding 'Insanity Defence' in Practice: What the Law Actually Means

Hey guys, so we all know the IPC's got this section 84 plea, but have you ever heard of someone actually getting it? I mean, the textbooks say it's a viable option for insane accused, but I've read so many judgments and can confidently say it never works in reality. The reason is - the law defines 'insanity' in the most narrow way possible. A person has to be proven completely devoid of understanding and not just a wee bit crazy. That's a massive hurdle. For instance, in the famous 'Bhagat Singh's case', the court rejected the insanity plea, citing the fact that Bhagat Singh knew the right from wrong but chose to do wrong anyway. Any real-life examples anyone can think of?