You can ask any couple that has been in a relationship for a few years.. or even months if their partner has changed emotionally. More than likely, their answer will be YES.

 Just some numbers:
The ratio of marriages to divorces is 2 to 1 (Marriages and Divorces).

Total Marriages showed a sharp drop in 1998.

The number of Unmarried Couple Households (living) is increasing steadily.

Due to more women becoming independent, instead of the men 'bringing home the bread', we have become more and more confident. Now days, we don't have to settle with just one man for the rest of our lives.

Marriage by mutual love evolved gradually. It was not until the 9th or 10th century that women gained the privilege of choosing or refusing their husbands according to their own judgment. From the many stories, legends, and myths that have come down to us from ages past, we know that love has always played a part in marriage. However, civilization had to advance beyond the primitive stages before marriage by love became accepted. In fact, the position of the woman within any given society forms an accurate gauge as to how far toward civilization that society has progressed. Whenever marriage by purchase falls into decay, then true civilization begins. On the other hand, a culture which practices marriage by capture is in the lowest stages of barbarism. In modern civilized life, marriage by capture occurs only as a symbol, and marriage by contract occurs rarely. Marriage through mutual love is the hallmark of a civilized people.

But the Christian population still has its way of steering us from divorce. Although widely accepted by most, this presents a moral problem.

"Marriage was the first institution established by God in the Book of Genesis, chapter 2. It is a holy covenant that symbolizes the relationship between Christ and his Bride, or the Body of Christ. Most Bible-based Christian faiths teach that divorce is to be seen only as a last resort after every possible effort toward reconciliation has failed. Just as the Bible teaches us to enter into marriage carefully and reverently, divorce is to be avoided at all costs. Honoring and upholding the marriage vows brings honor and glory to God. " - http://www.about.com/

This may seem like useless information to most, but it's only to show that most have came a long way from the 'old days'. Back to the point of the post. People change.. when I was 16 years old, I remember liking reading, sitting quietly, ice cream..etc. Now, I'm very different. I'm more of an out-going and social woman. This is the same as a relationship. I've seen a lot of 'high school sweethearts', walking, talking, and laughing.
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Most can be truly compatible when they first start dating, but don't get me wrong, some are capable of keeping that spark for years. What I'm trying to say is, it's only natural for people to change, it's only human nature. When you feel this change has happened, or is happening, it's best to confront your partner and explain how you feel you or him/her have changed. It's not a bad thing. But sometimes.. it can be. Human nature is going to take it's course as we live and grow. When we were all in elementary school, I'm sure (most of us) didn't even know what sex was, much less interested in it. See? Human nature had kicked in when you began puberty. (Of course you were already on the human nature course, it's just an example.)

I'm not an expert on relationships, but I've had a bit of experience and problems (most fixed and some that were unrecognisable.)

Summary:
If you feel that the change in you is effecting your relationship, simply let your partner know. Communication is the biggest part of a healthy relationship and needs to be tended to all the time.