It's also a rather useless truism, since it applies to everything, and if people followed it, nothing whatsoever would ever get done, and humanity would've died out in their caves long ago.
I'm very much like that myself and as I'm nearing my 40s, I started to regret it quite a bit. I started to think that the brand of individualism that we imported from you-know-where is somehow broken and dysfunctional when transplanted anywhere else. It's way too late to do anything about it, though, other than praying to Strauss and Howe and hoping the trend will reverse itself in a generation or two. Though, it might not pass, as their theory is also pretty closely tied to the environment and might depend on some factors we don't, or can't, replicate over here.
To the TeMPOral sibling comment: yeah, humanity survived in those caves by sticking together. I thinks it's important, and the fact that it took half my life to realize this is, in hindsight, rather strange and sus.