Maybe you've been in a relationship for years, or maybe you're just starting out with someone new. Either way, it helps to know that your romantic (and sex) life won't always be peachy keen.
According to Dr. Ruth Westheimer, better known simply as Dr. Ruth, the most common relationship problem she sees is people having unrealistic expectations.
"Hollywood and the movies tell us that the stars have to be twinkling every night," Westheimer told Business Insider. "That's not reality of life."
To be sure, Westheimer isn't advocating low expectations for relationships or sex lives. Her philosophy? It's important "to be realistic, but to still have hope."