Whilst the attention has concentrated on the effect of Brexit on the UK, do not forget the effect of Brexit on the EU. With UK within the EU, there has been constant tension. The UK have been often an irritation to other member states. This is because of the stresses between the original concept of a Free Trade Area and the ever closer union heading towards the European state.
The UK joined the EU to be part of the Free Trade Area. It never was committed to the “ever closer union”. It therefore was always trying to get exemptions or slowing down the move towards the European state.
For instance, the UK pound was the only EU currency not tied to the Euro. All the other countries of the EU (excluding Denmark, who track the Euro) are now required to join the Euro, when their Financial conditions are met.
The result is that EU can now concentrate on making a success of the Euro. Any country, using the Euro, would have a significantly more disruption to leaving the EU, than for the UK. Therefore, the EU/UK negotiations, should be less fraught, if it is recognised that the EU is not creating a blueprint for other Countries to leave.