I last tackled DF 5 or so years ago. Started from a tutorial on how to handle the interface, a step by step guide to building a fort to teach you how it works, and eventually, for a brief while, I had it down. I had a sprawling multi level fortress with magma forges turning out master crafted arms and armor, halls full of carved, decorated floors and walls. I diverted water from the river to a pond near my fort so that I could send dwarves up into a walled off area to safely fish, and since I already had the canals dug, I used the water and a series of pumps to make a waterfall in my main hall. Similarly my garbage pit was an elaborate construction, a massive shaft reaching deep down into my fort, so once again we didn't have to go outside to dump garbage, the fumes would just waft up out of the massive pit we dug. It was initially completely open on the surface, until this one goblin raid. My captain smacked a goblin, sent them flying over the pit, where they fell to their death in my garbage pile some 7 z-levels down. I built a wall around it after that.
My main entrance was eventually a massive, wide, winding ramp down from the surface with a closable door, lined with barracks and spots for my crossbowdwarves to shoot invaders from, and then built up around the entrance was a 3 story fort, above ground, made of stone. It was nuts to build, 4 towers, all connected, with the two flanking the actual entrance the ramp connected by a bridge at the second floor, and was home to my military training areas to acclimate my military to life on the surface and once again was lined with spots to fire crossbows from on the upper floors. And ah, the military; it's sad I can't remember her name anymore but my captain of the guard was a total badass. With her rather un-dwarfy spear she slew hundreds of foes, was legendary across basically every military and physical attribute, and was basically an unstoppable force. I could send her out alone against goblin raids and she'd have no trouble.
Alas, Dwarf Fortress is very much not like riding a bike, in that every time since I've tried to go back it's right back to being this dense, inscrutable mystery, and I just can't muster the time to learn it again, which is sad, because it was a lot of fun while it lasted.
@clg6000 It is very much more management than anything else*; you just assign your dwarves jobs(i.e. you're a miner), and then set up tasks that need to be done(i.e. these squares need to be mined), and then the dwarves figure it all out themselves. When you assign dwarves to the military, you tell them whether they should be training, or patrolling, or order them to go fight; then you set up designated areas where they can train, waypoints for patrols, etc. The interface is pretty tough to get the hang of, because for all they can be smart they can be dumb too(assigning gear to military dwarves is annoying; you can layer armor(i.e. leather under chainmail under plate), but you have to manually have them put on each layer one at a time, or they'll just slap on plate with nothing underneath).
Beyond that there are a lot of quirks that lead to goofy stuff happening. Case in point, the fishing hole I mentioned above came out of a particular disaster. Occasionally, a dwarf(it can be any dwarf, not just ones who are already crafters) would be struck by inspiration, claim a workshop, demand a list of materials and then get to work on...something. Often you hoped it'd be a weapon or armor, because when they complete this masterwork they get legendary status on whatever the craft is, and Legendary Carpenter just doesn't have the same ring to it. Anyway, there's one hitch to this system; if you don't have one of the materials they ask for, they start getting angry about it. I mean really angry. Psychotically angry. Which is to say if after a certain amount of time you haven't made the materials they're after available, they'll snap and go on a rampage through your fort. How does this tie into my fishing hole? Turtle shell. I had a dwarf who really wanted to make something with turtle shell, but I didn't have any. And no one who came to trade had any turtles. It didn't end well, though fortunately my hammerer(basically the sheriff) was right nearby when he snapped and ended things before they got out of hand(which is to say, he whacked him with his hammer until he died). I very quickly after this looked up where you get turtle shell, and embarked on my next engineering project...
*Edit: I should note, there is a rogue-like adventure game mode too, though it wasn't quite as fleshed out yet last time I looked. The neat thing about it though is, while you can have it auto-generate a world like the normal fortress mode, you can also use a Fortress mode game as the area you'll explore; you can explore your fort, either populated, or skip ahead years in the future. It's neat in concept but I never messed with it.