

A life jacket is what can help save you once you exhaust yourself fighting against a torrent of water. If you need to do something a bit reckless to save yourself or someone else, then it can help you catch your breath a bit and keep your head above water.
The thing is, if you are needing to rely on a lifejacket, the situation may already be a bit desperate. If you are able to get some kind of an early warning system, then that will go a lot farther at helping you get to safety. Getting a lifejacket could help make a difference if you are in a potential flood zone.
I feel you can be somewhat aware of your own beauty in that many people typical find partners that have a similar level of attractiveness to themselves.
Also, I’ve heard there are some narcissists that are aware of their narcissism. That doesn’t necessarily mean they are trying to subvert it though.
I think you can have a rough idea of your own intelligence in contrast of others, at least within a defined scope. But there are many different types of intelligences out there so it’s a bit of a spectrum. Especially comparing things like textbook knowledge of the field, on the job experience, interdepartmental knowledge, and emotional intelligence.