Being a Father - or Mother - is absolutely one of the most challenging roles we can play - assuming of course that we want to play the role and care. As the father of 4 adult kids (58, 58, 57, 55) and the step dad of one adult daughter (46), I have seen more highs and lows than you all might believe.
Those early years were so wonderful, but around age 15, its like "what the heck happened to them". And then you go thru some often difficult times, and one day you turn around and they are full grown adults. But at least for my wife and me, having a kid - be they 5 or 50 - is often a 24 hour and 365 day job.