I think the one in the cave is pretty easy, but then the Tree Sentinel right outside pretty much kicked my ass about 50 times.
Now that I'm pretty OP for the midpoint of the game (like level 140) I'm hunting down field bosses that gave me grief earlier in the game. Somehow I still get killed really quickly by normal enemies the farther I get into the game, though I'm not the greatest/calmest player. I basically stand up, dance around, and yell when I'm fighting a boss, and am probably best termed an "educate button masher," meaning I know what controls to use, but swiftly forget them when in a panic.
I have gotten better about inadvertently jumping off my horse mid-battle, though.