I found that as a man dating women I had to keep my feelings and desires hidden most of the time. I also had to act more assertive than I really am. And at some point those acts would become tiresome, and then the relationship would fall apart.
So, my recent attempt at lesbian dating... Well... It was much much shorter lived. But, it was very different.
Conversation was much more fluid and personal. Everything was more relaxed and comfortable. And I felt I was able to be much more open about my feelings and desires... Which, made it really easy for me to turn into a very emotionally intense lady without even realizing it and frighten her the hell away.

Though, post relationship analysis shows that she was right to run. I've always ALWAYS been a foolish romantic, and in relationships I was the person doing sappy heartfelt romantic gestures, because, quite frankly, I wanted to be the recipient, and knowing that wasn't going to happen, I tried to live vicariously by being the person who instigated the act. And, well, the woman in question this time, as much as she's totally awesome, and as much as she totally gets me in nearly every way, well, she's not the type to write sappy love letters, or send me flowers for no reason. And, those were the expectations I had hung over her shoulders.
Sigh. Live and learn...