/ic/ - Artwork/Critique

So I've been noticing I really struggle drawing characters I don't have practice drawing. An "Uh, duh." statement, I know, but usually from what I've seen, great artists tend to be able to draw any character with little struggle, even if it's their first time drawing character.

Could this mean my visual library is lacking and I need more practice drawing unfamiliar characteristics? Oh is my construction understanding lacking? (I mean, theoretically speaking, if I understand the form of the head, its features, and understand how to properly draw hair and clothing- I shouldn't be struggling THAT much drawing hair or clothing I haven't drawn before, right?)