Sif/Thor
Not all of these realizations have come from my time here, Sif. I have stood up to my Father. Watched my Mother die. Watched my Brother die. Battled timeless foes, watched cosmic forces at play. And yes, spent time with mortals and have learned that you must make the best of your time.
I can no longer always assume how things will eventually turn out, given a long enough lifespan.