i think it's just humour, i assume it's referring to rust's lifetimes which is a feature (mostly) unique to rust

There are many who are pushing rust as a religion tan that turns people off.

Half joking. Lifetimes can be hard but once you understand the concept it's quite easy.

The second joke is about you never learn Rust. You're always on the learning rollercoaster. Always one step away but each time it makes you rethink the whole language.

Don't get me wrong, I'm a rust main. But does issues does exist

Both. The people who promote Rust can be very annoying. They trumpet Rust's memory safety while turning a blind eye to any problems with the language, let alone the effort required to rewrite a large system and all the bugs such a rewrite will introduce.