Throughout the show's ten year run, the six titular friends proved time and time again that they are closer than family. While some were relatively new to the group, some of their relationships dated all the way back to college.
While Ross' own sister is part of the group, he is arguably closer to Chandler Bing, his oldest friend. Best buds since they met in college, Ross and Chandler basically grew to be closer than brothers. They even became brothers for real when Chandler married Monica.
Part of the reason they get along so well, and work together with such a strong dynamic for the show, is because they are so similar. They both have the same goofy sense of humour, both struggled in their love lives until they for far longer than they'd have liked, and both were just as geeky as each other.
That being said, the two differed in some big ways too. While Ross always knew where he wanted his career to take him, Chandler waited until his 30's to pursue his dream job, and of course, Chandler only got married once. Just how well do you know these two? Can you tell the palaeontologist from the transponster from just their past actions alone? Or did they experience these things together?
Answers at the end!