There are so many transfers in world football that it can be easy to forget every deal and move.
Whether it's major European clubs dropping transfer clangers or hidden gems rising from unlikely circumstances, some player-club combinations can be very easily forgotten.
Bearing that in mind, a new trend on Twitter has football fans talking and in the absence of a better phrase, it has been christened the 'I completely forgot he ever played for them' game.
The thread first appeared on @FPL_Partridge, but also bled on to other forms of social media and has opened up a forum for football fans to add the most bizarre collaborations.
There are just too many unlikely combinations to list in one article, so feel free to add your own in the comments, but we're going to breeze through some of the very best.
Most random player-club combinations
Hector Bellerin at Watford: What on earth? That's right, before making his name at Arsenal, the Spanish full-back accumulated eight appearances in the Championship at Vicarage Road.
Jerome Boateng at Manchester City: Although the German has recently declined, the Citizens probably wish they held on to him beyond a largely forgettable 2010-11 campaign.
Harry Kane at Norwich City: To be fair, we could easily have picked Leicester here as well, but Kane was already playing Premier League football with the Canaries before his Spurs bow.
Frank Lampard at Swansea City: The seemingly incumbent Chelsea manager made a handful of appearances in the second division with the Swans back in 1995-96. Who knew?
Shkodran Mustafi at Everton: Thought Mustafi first moved to England with Arsenal? Wrong, the German was actually part of the youth set-up at Goodison Park for fully three years.
Pierre-Emerick Aubameyang at AC Milan: It's hard to believe the Arsenal man spent four years at the San Siro, but missing out on a single senior outing made this spell rather forgettable.
Fabinho at Real Madrid: This brief collaboration was highlighted more after his recent Liverpool move, but who remembers Fabinho working under Jose Mourinho? We hardly do.
Alan Hutton at Mallorca: The fact that Hutton once went head-to-head with Cristiano Ronaldo and Lionel Messi will never fail to amuse us... not that we can recall it very well!
Gianfranco Zola at Kettering Town: Ok, something of a cheap shot here, but Zola actually made an appearance for the Non-League outfit during a tournament in 2007.
Eric Dier at Everton: Trust us when we say Everton are full of surprises and the fact Sporting Lisbon sent the Englishman on loan to Merseyside in 2011 is far from well known.
Nicklas Bendtner at Juventus: How on earth did this happen? Believe it or not, the 'Lord' himself was on hand to bag himself a Serie A title while enjoying a loan spell away from Arsenal.
Juan Mata at Real Madrid: If you thought Mata started his career at Valencia, you're not alone but it was through years of learning at the Bernabeu that he become the player he is today.
Edgar Davids at Barnet: Imagine having Barcelona, Inter Milan, Juventus, Ajax and AC Milan on your CV, only to move to the fifth tier of English football. Just ask Davids.
Ricardo Quaresma at Chelsea: Sadly, fans at Stamford Bridge didn't get to see the Portuguese's famous 'Trivela' shot on many occasions, but he pulled on the blue jersey nonetheless.
What's the weirdest player-club combination that you can remember? Have your say in the comments section below.