I'm the father of three step-kids and a rockin young daughter of five. I hit fatherhood when I married my second wife at the age of 39. I now have hair turning whiter by the day and high blood pressure.
Because teen stepdaughters are the devil.
There are times when I think that the problems with the older three shouldn't have been mine. The youngest of the three is pretty messed up (bi-polar, ADHD, ODD, clinical depression, mental processing speed of 8 on a scale of 1-100) and he's currently in a residential facility near where we live. The middle daughter is a hellion....sneaking boys into her room at 3am at the age of 14. Their father is a fucker, and has really failed as a human being when it comes to anyone in his life. But each of them has so many strengths that without them I'd be living a smaller and shallower life.
But in the act of giving them my heart and soul, I find I'm a better and happier man than I've ever been. It's in the facing the challenges and working through them that I can feel myself growing in ways I could have never comprehended had I not made the decision to be their dad. And along the way I've sort of found ways to teach them what I could about the things I feel are cool. Middle daughter loves Motown thanks to me. Older daughter is into Hitchcock movies due to my influence. They all have a wider appreciation of music genres and artists they'd have never heard of by now.
And my angel....well....fuck. She's just the shit. Talented and smart and curious about the world and her place in it. I am so totally in love that it hurts sometimes. She got a guitar for her fifth birthday...and greets me at the door each night to play "pretty songs" that she writes. And each night it makes me feel glad to be alive to be able to sit there and be told "no...that's not right daddy...you have to do it different" as she bashes the open strings through her little Marshall practise amp set on stun and sings "Mommies are the best, but they sometimes go insane"

At this point, I feel so far ahead of the game that it's beyond my comprehension how I made it this far without my kids. All of them. I'm blessed beyond measure.