In Chrome at least, having the devtools panel open[0] disables {all,most,some,infuriatingly inconsistent} parts of the cache system, so every refresh is a 'hard refresh'[1].
[0] Might be an option in the dev-tools settings, but I think it's enabled by default.
This is true, and I always have that option checked.
But if I am on a site that seems to be loading the old cached stuff during my regular browsing of the internet (not building stuff) I always open dev tools and refresh to do a "hard" refresh.
But learning that CTRL-F5 does the same thing is really neat, and I feel very silly at the same time!
[0] Might be an option in the dev-tools settings, but I think it's enabled by default.
[1] Except when it's not, of course.