It appears to me that by deciding to use subjuctive in the second clause of the sentence, creates the doubt. Therefore, however I set up the statement does not really matter. Generally, I will have created doubt. I am guess that generally the doubt it pushed onto the first clause, meaning:
Me alegro de que hayas viajado a diferentes países.
I am pleased that you have travelled to different countries.
Me alego (I am pleased, as long as it was pleasing, but maybe it was not so pleasing for you afterall)... or is it that I am pleased, but you may not have really travelled the world. Which is the sentiment? Am I on the right track? I am guessing the first.
What is the sentiment if I were to say "Estoy feliz que hayas viajado a diferentes países".
