Something about wood that impressed and surprised me as a newb (still not far from that distinction) was the concept of wood movement, and how very alive wood remains long after its been felled, sawn up, and dried. Just search Google for "wood movement" and you get 137k pages on the subject. Just the first few are enough to learn a lot about it, and there's even
a handy calculator from one of my favorite online wood shops. Wood moves a lot across its grain, and almost not at all with the grain (something like 0.1% on average). The way the wood is
resawn matters, too, so learn a bit about plain sawn/flat sawn (most movement), quartersawn (less movement), and riftsawn (least movement, least available (hardest method of resawing)). There's also an element of aesthetics in each of these. Sometimes you just want the cathedrals seen in plain sawn lumber. Sometimes you want the thin, consistent stripes of quartersawn.
Some anecdotes I've heard about wood movement include tables cracking loudly in half down their lengths, right through the center, antiques that have been fine in antique shops and homes in one place for 100 years being purchased and brought to another place only to have the change in humidity cause them to warp, bow, twist, and crack, and I'm on the list of having a lot of my projects fail months later, because I didn't properly appreciate how very much wood moves. I've made things that slide easily enough when made bind completely later - beyond any mechanical means of moving them ever again - because I made things that should slide fit too perfectly together. I was even proud of my perfect fits
I turned a Eucalyptus cup on my lathe with a base exactly the diameter of the faceplate it was screwed to, even sanding it and the faceplate a bit when finishing it - they were flush. A month later the cup was nearly 1/8" shy of the faceplate all the way around, or nearly a full 1/4" thinner, and it was only about 3" wide to begin with! In fairness, it was made from a fairly green limb, but still, I was shocked when I saw it sitting there on my workbench.
Things like rail-and-stile cabinet doors came about because the panels inside need room to grow and shrink inside the grooves in the rails and stiles. I didn't know this earlier this year and glued some pretty poplar panels into their frame grooves. I'm worried that if I ever move, those doors are going to crack all over in their new home.
Oh, and one last thing about this - good woodworkers tend to buy the wood they need for a project, then stack it up in its final location for a few weeks to let it acclimate to that location. Some even leave it in a kitchen where it's destined to become cabinets, or upstairs in an office boardroom for a month, then go pick it up when they're ready to build. They'll mill the wood (cut, rip, plane, etc) and assemble everything ASAP. It's not good to cut up all your pieces, then leave them sitting in your shop for a week before you get back to assembling. They'll warp again, even if just a little bit. Fit won't be as perfect. For a lot of things it's okay, but if you want really perfect, pro-level work, they tend to follow these steps religiously.