In order to excel at anything, there are always hurdles, obstacles, or challenges one must get past. It's what bodybuilders call the pain period. Those who push themselves, and are willing to face pain, exhaustion, humiliation, rejection, or worse, are the ones who become champions. The rest are left on the sidelines.
In life, people tend to wait for good things to come to them. And by waiting, they miss out. Usually, what you wish for doesn't fall in your lap; it falls somewhere nearby, and you have to recognize it, stand up, and put in the time and work it takes to get to it. This isn't because the universe is cruel. It's because the universe is smart. It has its own cat-string theory and knows we don't appreciate things that fall into our laps.
What's interesting about Casanova is that he isn't so much a simple womanizer but someone who has lead a really amazing life. How hard could it be seduce someone, when you are a charming charismatic adventurer. I'm only finished with Volume 1 so far but in my opinion, Giacomo Casanova is a classic version of James Bond.