When it comes to anything and everything really, change is inevitable. Slight or significant, better or worse, it doesn't matter. At different times in our life, different things in our life need some revamping because of the pure monotany of it. You have to reaccess and do something about it. Otherwise, it gets either stagnant or changes from other sources outside your own.
I know I'm being as vague as possible but I'm actually getting to the point which is rare. Like having a job for example. You work there for months, then years, you get to a point were you can't progress any further and then what? You got to change it up somehow, either do more or different things, go to something new completely.....to each there own. You get a house, you make it just the way you want and then years go by and you got to update. (Well, you don't have to but then your shit's outdated).
In relationships, you got to be more creative since we live in the expected monogamous society where you find a mate, latch on and go through your whole life with that person. After a while......long while, it's not as easy to go on to something new. You've made a commitment to that person and yada yada.....The hard thing is to keep coming up with shit that's different to liven it up.
What if by default, you're not all that creative and either is the other person. That can turn it to a sorry route of 'same ole same ole' and stuck in a plateau for a good while. Don't get me wrong, you can always breakup and move on but really, even if you find your soulmate and you're super compatible in every way, there will be a time that the honeymoon is over.
Back to my point, when it come to anything, over time... things will change. It's best if you have control over it. In order to do that though, you make the initiative, put forth the effort and try to create change for the better. If you go into uncharted territory, who knows the outcome.....could be bad, could be good. Just make sure you try.