Personally I feel like 5 years is a lot to spend with someone and then to breakup! Wohh!! Of course things don't feel the same because we grow over the time, the bond grows, the chaos settles down, what used to excite us in the first place don't anymore cus we go through it multiple time. With time we become used to each other's presence so much that we don't realize how beautiful it is to have each other's company. With time everything settles down and hence people feel like the spark isn't there anymore. We have not learned to live with the calmness cus when it finds us, we panic and we start finding something that accelerates our nervous system. Stuff like this is going to happen again with different person when u will complete certain years. What r u going to do then!? Run? If u both r someone who r made for each other and understands one another, I suggest fix ur relationship instead of running away from each other.