As the classic pop song says, "to everything turn, turn, turn." The song is based in good source material... the Bible.
To every thing there is a season, and a time to every purpose under the heaven:
A time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted;
A time to kill, and a time to heal; a time to break down, and a time to build up;
A time to weep, and a time to laugh; a time to mourn, and a time to dance;
A time to cast away stones, and a time to gather stones together; a time to embrace, and a time to refrain from embracing;
A time to get, and a time to lose; a time to keep, and a time to cast away;
A time to rend, and a time to sew; a time to keep silence, and a time to speak;A time to love, and a time to hate; a time of war, and a time of peace.
What profit hath he that worketh in that wherein he laboureth?
Things change. That doesn't take away from the value of them at the time or the value of the new season that follows them. That seems simple, but it is a concept that we as humanity have a hard time accepting. Change is life. Like a shark, you cannot sit still and remain alive. Whether it be romance, money, or whatever... you must keep growing, changing, and lighting the fires each day. Otherwise, it is just dead that has yet to fully materialize.
You cannot live in the past. That is the past. You must live, NOW.
In one quote from Doctor Who that I absolutely love he says...
"We all change, when you think about it, we're all different people; all through our lives, and that's okay, that's good, you've gotta keep moving, so long as you remember all the people that you used to be. I will not forget one line of this, not one day, I swear. I will always remember when The Doctor was me."
People are always trying to find and be themselves (myself included), but that is a fluid concept. We are in a large part the face that we show to whatever environment we find ourselves. When in a negative environment, we are negative. When in a positive..positive. When with a partner, romantic...when with an enemy, defensive. And, ALL of those are us, and all of them are good.
What we need to do is find the right environment that will allow us to be the kind of person that we WANT to be or that makes us happy. However, we don't always will be, since we only know the past. If we want to have a different outcome, it will take a different path. So, when changes come, welcome them with the sense of adventure to wait to see what person you can be within them.