NOTHING.... It's a nonsense word I just pulled out of my ass! Every time I turn around, you damn kids are inventing new words (bae, cuz, imma, gurl, bragh, droog, brohanski, etc.,) so I figured WTF! If you can do it, I can do it ! ! !
Hey, we're just joshing around because you tried to make a joke that doesn't exist.
If you look at an Eye Chart, you will see 20-20 vision. So if you start out in 2015 and say "where will you be in 5 years?" you can pull out the 20-20 joke.
People just messed with you because:
#1) You said "21-21" vision in your meme and we all know 2121 is 105 years away, not 5.
#2) Even if you would have said 20-21, it is not 'funny per se' because 20-21 is not on the Snellen Eye chart.
I remember last year when I called Kermit a reptile in a meme comment and was blasted! But, man, when I read all the meme comments about how I blew that one I LMAO!! They were just as funny as anything I've seen on the front page!
So, I guess my advice is move on and laugh at yourself sometimes!
p.s. The next measurement on the eye chart is 20-25 vision.