Honestly its hard to reach this amount of bitcoin even a 1 bitcoin is hard to collect in 1 month..
It obviously depends on the skills you offer or the type of knowledge you hold.There are people making tons of coins a day and without much involvement of theirs.
But if you wait in years i think you need 100 years to collect 50 or more bitcoins..
I think even in Africa people can earn more than 1 bitcoin a year,so that is not true.
if you life at asia i think 100btc is more than enough to retire
Might be possible in Zimbabwe and else too.