Hi Razvan 94,
Sorry to hear that you failed phase 1 at Maastricht. You are allowed to reapply at Maastricht, but you are only allowed to be tested at Maastricht a maximum of 2 times, so in other words if you do decide to go back that is the last chance that they give you. They reimburse the funds each time you go and you have to leave a minimum of two years before you can reapply. The only way in my opinion that you can prepare is just knowing what sort of tests that are involved. Even if you know what is coming and have practised it before, the tests that they make you undertake are designed so that they can test you on your natural abilities and not what you have studied.
If you do reapply, then whatever happens you know that you have done the tests to your full ability and then it is like a closed chapter and you know for sure what to do next.