Lǎo péngyǒu jiànmiàn, tiānnánhǎiběi de liáole qǐlái.
The old friends met and started chatting about everything under the sun.
Tips
usage
Two distinct senses: (1) geographically — people or things from widely scattered places; (2) rhetorically — a conversation that wanders across any and every topic. Context makes the sense clear.
memory
天南 (southern sky) + 海北 (northern sea) = from the farthest south to the farthest north. Variant: 天南地北.