This isn’t always true, but in general, you can tell by how you feel whether something is very likely affecting your long term health.

If you truly feel fantastic staying up for days on end, and then sleeping extra for a while ... I know at least one hyper successful person who uses to be the same way.

She eventually outgrew it, and stopped.

I am skeptical this harmed her long term.

Now, lots of behavior makes you feel great and is in fact terrible for you ... but even obvious ones like drugs tend to be felt in subsequent days, same with that awesome tasting cheeseburger, etc.

So I think it’s worth it to at least entertain the notion it isn’t as harmful to pull all nighters for you as is commonly said.