I remember Feint being one of the most ridiculously overpowered skills in Final Fantasy history, but it had nothing on the old level 20 Thaumaturge trait (once you purchased it) that gave you increased defense while casting. Anyone who partied with a Thaum who had that knows what's up.
I remember looking for 3 hours on two occassions for a better weapon on my 36 pug than my broken Dodoskin Cesti I bought from a vendor at level 19. Stupid market wards.
Travel was so slow and tedious that I leveled miner JUST for the skill that gave you a speed boost when you search for a node and one isn't near you.
I remember Cactuars and the 1000 Needle spam, and Jackals and their spammable full-HP drain bite. I hated those bastards.
I remember running out of inventory space by getting Alumen/+1/+2/+3, Copper Ore/+1/+2/+3, Yellow Copper Ore/+1/+2/+3, and Tin Ore/+1/+2/+3 from just outside Ul'dah. Oh and Marmot Meat/+1/+2/+3, Mole Meat/+1/+2/+3...
Oh, and getting a crapton of Biast Scales and Drake Scales off antlings in Copperbell mines. We had no idea if those were worth anything but ZOMG DRAKE SCALES!