connections on a train

I was on a train coming back from Leeds and got chatting with the guy opposite me, who reminded me a bit of my friend R I'd met on the train 12 years ago. As the conversation went along, I learnt that he (M) worked in Haematology and was doing research in Leeds. R works in Haematology research at Sheffield University. Knowing that the Haematology world tend to be aware of what they are doing, I asked if M knew of R, He said his name rang a bell, but wasn't 100% sure, so I text R to see if he'd heard of M. R said he'd just been reading a paper written by M. This intrigued M as his papers were very specialised and so asked what R was working on. R was working on putting one of M's theories into practice. R then asked for M's contact details, which was what M was just about to ask. My friend Lynn who was with me said that was amazing, but I just said "we're far more connected than we realise if only we talked to each other more often.