Is there a pattern or skill that you don’t yet feel ready to tackle but which you hope to (or think you can only dream of) tackling in the future, near or distant? Is there a skill or project that makes your mind boggle at the sheer time, dedication and mastery of the craft? Maybe the skill or pattern is one that you don’t even personally want to make but can stand back and admire those that do. Maybe it is something you think you will never be bothered to actually make bu can admire the result of those that have.
I don' t really understand the idea of feeling "ready to tackle" a skill. In my experience, you see a project which demands that skill, and if you like it enough, you're going to make it. I haven't done much teaching of beginners, but I'd always say "whatever you want to" when they say "what should I make next?". I've seen people working on both-sides lace projects when they've been knitting for less than a year, and people happily cranking out garter-stitch blankets after many years' experience.
Having said that - yes, there are things which make me boggle. There were some fabulous crocheted scarves at the last two years' I Knit Weekender, made by someone with a French name (please, anyone)? in what looked like #8 perle cotton. There was an Irish crochet wedding dress, a photo of which was shown to me on a train, because the husband of the woman who'd made it in the 1970s wanted to take a phone-video of me knitting beads into a shawl using a crochet hook. (The bride had also crocheted bodices for her three bridesmaids; he didn't have pictures of those). Anything at all Debbie New does just alters my brain in strange and subtle ways.
I'm very glad I started knitting when I did, and where I did; there was no notion of what was easy, and what was complicated, because I really didn't know any other knitters, apart from girls my age and one or two of their mums. In some ways, obviously, this made the task harder; but in other ways, there were no boundaries. I've learned more in the last 10 years than I did in the previous 15 about knitting, because of the Internet, but I've also learned that some people think there's a right way, and a wrong way, to do things; and that's not always helpful.