hashem needs to be thanked not just because he answered your tefillos but because you are alive and breathing this very second!
many times we make the mistake of only thanking hashem when its something big!
its with missing the train too…why do we tend to only thank hashem when we here the train/airplane had a crash or accident and we missed it? even if nothing happens we should be thanking him because if he did it it is only for our benefit!