Yes, there is some Buddhist-flavoured insight in there.

1) you cannot control the world around you

2) you can only control how you react to the world around you

3) to tie your happiness to things you cannot control is to suffer

Once you internalize this, you will identify attempts to circumvent this truth, and why they are ultimately self-defeating.

Pretty interesting that you map this mentality to Buddhism, when I knew it from Stoicism.

I wonder if they ever influenced each other, or if those principles where 'discovered' independently ?

To me it certainly seems like they share some core insights. The main difference is meditation, which is really the core of Buddhism.

> 1) you cannot control the world around you

It's definitely not either/or, sometimes you can change the world a little bit by making a post that says "please be nice".

Or the way I see it: be prepared to step in shit sometimes but if street defecation is not culturally accepted, your walks will be nicer.