I think the obvious problem with this is that people only really keep track of their own clubs transfer rumours. Some of the more transfer obsessed fans are getting excited by every rumour and whisper, so in their mind their own clubs transfers take ages, whereas they don't keep up with the same whispers from other clubs so only find out about them when they are at a late stage, so they perceive them to be quicker. Kante to Chelsea has been rumbling on in the background since about halfway through last season, but in his mind he seems to think they just decided yesterday and got it done today.