Well, the 'synonym back story' can be quite interesting. Take the words 'happy' and 'glad'. Their back stories may be related to cultural and historical usage. In different regions or time periods, one might have been more popular than the other. It could also be related to how the human perception of positive emotions has been expressed through language, which led to these two words having very similar meanings.
Sure. Consider 'wise' and 'clever'. The back story might be that 'wise' has an older origin and often implies a deeper, more profound knowledge and good judgment, perhaps with roots in Old English. 'Clever', on the other hand, might have developed later and often emphasizes quick - wittedness or ingenuity in a more practical or immediate sense.
Rebirth from a dead end was synonymous with rebirth from despair, rebirth from despair, rebirth from death, rebirth from nirvana, rebirth from cocoon, and rebirth from nirvana.
Splendid was similar to resplendent, gorgeous, magnificent, wonderful, brilliant, glorious, gorgeous, bright, beautiful, rich, gorgeous, gorgeous, brilliant, and so on.
The synonymous words of great momentum were: great fanfare, magnificent mountains and rivers, all-powerful wind and clouds, swallowing mountains and rivers, vast seas, ten thousand horses galloping, magnificent, heroes achieving success, and majestic.