Perhaps that was not fully and constantly brought home to decision-makers. Instead, they seem to have assumed that all problems of macroeconomic imbalance would automatically be self-correcting in the new environment.
For example, by removing the possibility of devaluation, membership of the euro ensures that any country which allows its competitiveness to get out of line will ultimately suffer a costly period of adjustment likely associated with unemployment. It was always going to be much more difficult and more painful to readjust aggregate competitiveness. Did that stop countries from losing competitiveness: no! [Chart 6].