So your legs are feeling good?
Hill classification is kind of meaningless, in a race they are classified relative to the stage they are in. A hill might be listed as Cat4 in a flat stage that wouldn't get any classification at all in a hilly stage.
I've done a bunch of Strava HCs, Strava puts a ton of emphasis on total work (kJ), so long steady climbs are going to be 1s or HCs. So there are HCs that are actually really easy to climb, while I know of a Cat3 that will make most recreational cyclists walk their bike. In a race, road conditions are considered too, so a rough gravel road that requires you to be out of the saddle balancing your weight might get a higher classification than if the surface was smooth asphalt.
I've done quite a bit of climbing on dirt and gravel roads, and snow packed roads with 23mm road tires @ 110psi, and that makes anything other than a gradual ascent much more difficult. So, no scoffing here.
