In on-line dating site forums which I have frequented, there is a guideline reputedly called the "Rule of Kings" which recommends that the maximum age difference between two potential partners should be one half the eldest person's age plus seven years. Therefore, according to this guideline, the minimum recommended ages for partners with a 15 year difference would be 29 and 44 years old.

That being said, when I was 25 years old, I began dating a man who was 40 years old. We dated for three years, living together for two of those years. Although we enjoyed one another's company very much, we were at vastly different places in our lives. He had been married three times, already, and had three children (two 19 year old boys and an 8 year old boy). He was only the fourth man I had dated. I had taken my first professional position two years prior (we worked at the same company). After three years, he took a job in another state. Although he asked me to join him, I was not ready to commit to him for life. We parted friends and still maintain contact as friends.

Each circumstance will be different. Only you and your potential partner can really say whether there is enough common ground to support a relationship. My opinion, however, is that you should pursue it and see where it leads. Nothing ventured, nothing gained.