Http - Do files with expires headers send requests?

Question

I just read that files that do have Expires Headers should not be requested again until they expire.

While testing some caching stuff I wonderd why files do have a size and do consume time on "Content Download" on chrome dev tools, even if they got a max-age set and should be loaded from cache without sending any request?

Any explanations?

Answer 1

Quoting from this answer:

Chrome appears to be ignoring your Cache-Control settings if you're reloading in the same tab. If you copy the URL to a new tab and load it there, Chrome will respect the cache control tags and reuse the contents from the cache.