the use of the phrase is a reference to the taped phone conversation of 50 Cent and Young Buck (When Buck was crying, he stated "I was wrong and confused" about the issue they were having)
Its used in a similar way as saying "cold-blooded" while making fun of your peers...
This is when you are trying to be hectic doing the Bondi Run, but realised your mate is actually the Bondi King now and you can't keep up, so after taking 2 minutes to make up and excuse with awkward silence, you use the excuse "I was in the wrong gear"
Comments Kids type in that you'll find in popular 21st century VEVO Music Videos such as Justin Bieber, Taylor swift, Katy Perry and many more . What It Means is that they wanted to be born in the 70s, 80s, and 90s cause they think that back then, The 70s, 80s and 90s had better music like Pink floyd, Nirvana, Green day and all the 90s rock band. But If they were born in the generation they wanted to be, There will be no iPhones, Good tablets and Call of duty.
Annoying 11 year old: I was born in the wrong generation, Katy Perry music is awful, Green day is much better. Why don't we have that today?