What do you pack on a hike?

Hi! I'm very new to hiking. After a couple of gorgeous trails this weekend suddenly it's all I can think about, I'd really like to start hiking regularly.

While my fiance and I were hiking over the last couple days, I realized we didn't really pack well for safety. We basically just had our water, picnic, and spare socks. If we'd gotten lost, injured, or even just accidently stayed out till sundown, we'd have been screwed. That said... the pack was still fairly heavy, and the trail wasn't easy even if I were unencumbered.

When I googled "hiking safety," I found the US national parks service lists the Ten Essentials that apparently everyone should have when recreating outdoors. I understand the reasoning for everything on the list, but when I imagine carring it all through a strenuous or long trail, I'm already exhausted. Like... Do I really need to carry a whole-ass tent through 8 miles of mountain?

Anyway, that finally brings me to my question: what do you bring with you to a hike? Presumably one that won't take longer than a day? Do you always pack all 10 of these essentials?