I have 3 kids from a 22 year marriage. It's not only having and raising them, it's everything you learn when doing this. Most dads learn very early that they are no longer number one and that they have to take a back seat to their children. Hold a baby in your arms and you'll understand how vulnerable and dependent on you they are. You learn a lot about yourself too. You go through all the phases of their lives, joy, sadness, sickness, courage, accomplishments, love, anger and so much more.
It's definitely not always easy and there are times you want to give them away, but in the end, there's nothing that makes you happier than seeing your children enjoying life and beginning their own families.
I'm blessed to have 3 great kids and even more blessed now to have 3 granddaughters. My partner and I get to babysit a 7 year old and a 6 month old tomorrow and we could NOT be any more excited