My first successful fort was called Heavenshatchet. Epic name. I saw my first goblins at Heavenshatchet, learned to build traps, tried out all the different industries etc. I also learned many of the ways in which things can go horrifically and hilariously wrong. This is a very long story but it's all relevant so bear with me.
Early on in the second year I realized I needed to protect the entrance. Heavenshatchet's entry was dug into the side of a small hill, so I decided I could just build a wall around it. I did so, and drafted the woodcutter I'd brought with me to patrol the gate. She was married and shortly after this had a baby.
And then... the ambush.
This is the point when I realized what those triangles were: ramps. The goblins just walked right up onto the top of the wall. Here they could fire their crossbows right into the doorway. The axedwarf charged them and a goblin maceman hit her baby out of her arms - it flew six tiles and landed in pieces. This is the first gore I have ever seen in Dwarf Fortress and I am horrified. But it doesn't stop there. The axedwarf falls, half a dozen recent immigrants fall, two more of my founding seven die, the dogs all die. We have no defence against them and no door. They rampage freely through the fort before eventually getting bored and going home.
I start work straight away on repairing and improving my defensive wall, grim-faced and determined that no goblin shall ever again step within the halls of Heavenshatchet. Goblins are evidently too dangerous to fight (I hadn't realized you have to ARMOR your soldiers) so the only option is to defeat them by dwarven engineering. The mason discovers mechanisms and starts filling a long extension to the wall with stonefall traps, weapon traps, bridge/channels, multiple shutoff points, catapults and ballistas: I name this Operation Clusterf*** (excuse the language). I still have screenshots of this thing somewhere.
(Humorous aside about the Clusterf***, shortly after its completion I had an elf caravan arrive. The elves started to head down the Clusterf***, at which point one of the new siege operators sent a lump of granite whizzing over their heads. They calmly turned their animals around and started walking back out.)
Anyway, while this monstrosity is being built, the fortress is teetering on the edge of a tantrum spiral. I have lost three of my founders to the goblins, several other dwarves are laid up with serious or crippling injuries - most notably a wounded butcher goes beserk and strikes down an immigrant dyer and several pets before being dogpiled in the middle of the dining hall. This is the first beserk mood I have seen and I am now thoroughly traumatized. The only dwarves who are not flashing red arrows are migrants who arrived after the Goblin Attack of 1052.
My mayor is especially unhappy. The captain of the guard (she whose baby was used as golf practice) was his best and oldest friend. At some point, while I'm watching elsewhere, he starts a fistfight, but evidently picks the wrong guy to mess with, because the first I know of it is when I get a message that he's "resting injury". I check, and he has a mangled arm and leg.
Tantrum spiral is, however, averted, and the fort slowly settles back to a semblance of normal life. There's another sticky moment a couple months later when the last goblin-injured dwarf dies (bleeding to death from a stuckin bolt I didn't know to dump) and his wife goes melancholy, but nobody cares about them much so it's okay.
The mayor will remain in bed for two more years. The liaison settles down patiently at his bedside for a long wait. He's seen this all before.
Autumn of 1053. The Cluster**** proves its worth by mincing two goblin ambush squads. We put their weapons to work in more weapon traps. We also accidentally kill a human caravan by dropping it into a channel (Urist, did you pull THAT lever?? I told you to pull THIS lever!!) but that works out okay too because we get a bunch of steel serrated discs. The only cloud is that dwarves are complaining about the nasty water and the lack of a well. Anyway, I get the bright idea to make my dwarves a well! From an underground cistern so they don't have to dash out of the Cluster**** to get to the brook when there's a siege on! Brilliant!
I get my two legendary miners to start channeling a circular shaft down into the ground. They'll be able to get out at the bottom via a ramp, no problem.
I am now distracted by a shortage of food and have to go kill a bunch of our animals to tide us over.
A couple months later, I happen to glance at the corridor leading to the cistern and notice a big cloud of miasma coming up the corridor. We have a rat problem so I assume one of the cats has killed a rat down there - but there seems an awful lot of miasma for a dead rat. One of my miners throws a tantrum, then her baby throws a tantrum. WTF? (I should add at this point that I don't know how to zoom to a dwarf from units menu, so the only way I can find someone is to look manually).
I find them at the bottom of the cistern, of course. One of the miners has just starved to death, and the other is starving along with her baby.
I tell the remaining miner to dig out, dig out, quick! There's a corridor only a few tiles away... but she dies before she can swing the pick. Now only her baby is left in that pit with the decomposing corpses of its mother and the other miner. That's two more of my founding seven gone, and they had our only two picks. The dwarven caravan has just left.
I now discover the metal industry. You, cut that tree! You, burn it! Someone find some metal ore! Oh thank God, we've got copper. Forge a pick! What do you mean you don't know how? Someone build a forge! Dammit I am not going to lose that kid!
A trembling peasant takes the pick, still hot from the forge, and starts to clumsily hack his way through the rock, down to the cistern base.
Little Mebzuth starves to death just as he breaks through the last wall.
The kicker? I now find out that the miner and her baby were the wife and only child of my bedridden, unconscious mayor.
ps: I never did get that cistern filled. I was convinced it was haunted, and really, would you want to drink water out of a place like that? We ended up using it as an execution chamber for captured goblins. The goblins who caused the whole mess by killing the captain of the guard and her baby. I like to imagine that the last thing they saw as they hurtled down through the dark was the vengeful ghost of Mrs Uzurist.
The mayor didn't go mad by the way, he woke up two years later ecstatic from all the nursing he'd gotten. "...I had a wife?"