Someone once gave me a manuscript and it took eight pages to get the heroine awake and out of bed. Another three pages lapsed before she got out of the shower. She kept remembering past events and thinking of terrible trials she had endured. I don't know what happened after her shower: I put down the manuscript. I didn't care.
If we can't identify in some way, we won't continue to read (unless forced to do so in a literature class). We call it reader identification.
When we read (and this is just as true with watching a film or TV), we become at least one of the characters and that transcends gender and age. The story or the character touches something inside us. We become involved in the story.
When I was fifteen I read The Human Comedy, which none of my friends then or since has liked, but I hooked into every character, especially the teen-aged boy Homer or the drunken Mr. Grogan. Markus was Homer's older brother and away in service. I felt the pain and the heartache of the family when they learned of Marcus's death.
One book won't appeal to everyone, but I've seen too many manuscripts where we have no one with whom to identify or care about.
Good writers make us care;
good writers work hard so readers can identify with their characters.