Above poster is talking about thinking in terms of grouped lifetimes and bulk allocations/deallocations, which is better for performance, and makes Rust borrow checking and other RAII style features completely pointless as they don't add any safety benefits. I used to think like you until I watched this video: https://www.youtube.com/watch?v=xt1KNDmOYqA

I can confirm after exploring programming like the above video explains, that everything he says is completely true.