Five years after the collapse of Lehman Brothers, those complaining about tighter regulations do not have long enough memories about the crisis, according to the man responsible for many of the European Union rules introduced following the collapse.

"There are so many people suffering, in the U.S. with the housing crisis after the sub-primes, in Europe on a social level, we do not have the right to have short memories," Michel Barnier, European Commissioner responsible for financial services, told CNBC at the weekend's meeting of euro zone finance ministers.