Why do people lose their "spark" after like 4 or 5 years of being with a person?

I think after so many years of being together, couple become too comfortable with each other. This is more than spark. This makes relationship to be easy to handle,easy to understand and smooth sailing prevail. When relationship goes sour, this is because many are still hidden, many secrets and therefore demands are out and seldom meet!

Hi mark98, your question is very telling! Why is it that you THINK everyone gets tired of their mate after only a few years? Your question needs to be different; rather than your question, why not say, "Why do people leave after only a short time together?" It's a matter of perspective! If one goes into a relationship not fully committed to that "forever after" kind of love, and perhaps, says, "Let's try and see if we can last", they are literally DOOMED TO FAIL!! Why start something as special as a interpersonal relationship, with anything less than 100% of the all-out effort? Anything less is not good enough. Marriage, having children, raising a family...That's all very grown-up stuff! Don't try any of it, if you're not ready to really WORK! Just look at the consequences of broken families. Children being reared by the babysitter, brothers and sisters living is separate homes, step-parenting issues, etc. Kids have it hard enough, and to compound Mom and Dad's issues are truly unfair! Marry for keeps. Stay in love with your mate. Tht takes lots and lots of hard work. We need to overlook all the little (and big) gripes and hangups. If we treat our mate better than we did when we were dating, love would be everywhere. My sweetheart and I have a date each and every week. Some dates may have been a simple walk around the block, or a soda at the convenience store. No matter how much money is spent; it's the time spent together that will keep love going throughout the years. This is the most important relationship you have, outside of yourself and God! Treat your mate with kindness and respect always.