Firsts and Lasts

So I've noticed that as we get older there are fewer and fewer "firsts" for us. Whether it be a first kiss, first day of school, first car etc... Which makes me wonder: as we get older to the "lasts" become just as important as the firsts?
I'm 25 years old and I know there are some firsts for me yet to come: My first (and hopefully only) wedding, my first child, my first real grown up job after my PhD, my first grandchild etc.... but recently I've noticed that I am looking forward to the "lasts" in life: The last day of classes, the last time I will have to take a test, and the more meaningful ones like: my last first date, the last man I will ever kiss or hug or sleep next to etc... And to take that a step farther I realize that even though I may not have been my man's first kiss or slow dance I will be the last person he says goodnight to each night and I will be the last person he ever kisses or sleeps with, and I will be the last person he falls in love with. I feel like those things mean even more to me than those silly junior high/high school "firsts"
And its funny to think about but maybe two people can find all kinds of new "firsts" just to feel young again. like maybe the first time you shout from a mountain top or the first time you kiss underwater or the first time you go to a new country etc... There are so many "firsts" that if you really want to have them you never have to give them up or settle for anything less than perfect!
Maybe I'm just growing up or maybe I'm just finding justification in my feelings but either way I'm ok with it.
So here is to all of you who have found your "last" man or woman and who knows how many "firsts" the two of you will come up with!