No/Yes,i said yes because sometimes age gap may create physical constraints.No because there are people who married much younger than of there age more than 25 years gap.So every relationship has some problems either age difference,financial problem.It all depends how they understand each other and how chemistry work.
I have attached few pictures as proof for your answer.1)First picture is american women marrying young man with age gap more than 25 years man age is around 23-25 i think and women age is more than 45 years there married 4 years back they are living happly in India,second picture is of Russian parliamentrian marrying a bar attender Indian boy from poor family and living India happily and remaing one girl is from California marrying India farmer living happly i India.This stories of couples you can find in youtube.
Yes there exsist couples who over come age,financial,tradtional,cultural difference married and living happly