Michelle wasn't the only woman in his life
It’s quite rare to meet someone who has only been in a single romantic relationship with one person in their entire lives. Once you start meeting people for intimacy, you learn things about what you want in a partner, so you may not stick around with that initial person for very long. Your tastes in people and needs in a partner may also change with age and life situations.
Our 44th President Barack Obama is no different than anyone else in that respect; he dated several women before finally falling for Michelle, and we’ve got all the details on his former lovers.
Obama was a young, handsome, charismatic, and highly-intelligent young man with big political dreams, and there were plenty of women who were attracted to him.