Fathers matter. If you're in any doubt, go and listen to the people who didn't have one - like in prison, or a Narcotics Anonymous meeting. Inadequate parents left many of them alone on a stony path to adulthood, or to nowhere.
Struggling, deprived and resentful, many were not there for their own kids. If you're out-of-it at your son's birthday, you might not remember it, but your son will, and not in a good way. Keep that up, and all you'll have is missed opportunities. If this is you, aim to be the father you wish you had.
Stress: Respond, don't react.
Your kids will have to compete in a tough world. We're descended from the ones who responded best to the challenges of the past, so your kids, inside them, already have the potential to be resilient. A dad who's responsible, independent, and faces up to adversity can bring out the character they need.
That's good, but it's not enough. We're evolved for challenges like not enough food, and running away from a leopard: things are less straightforward now. There are fewer immediate threats, less scarcity, and we are drowning in distressing information. We're less evolved to deal so well with the long term stresses of modern life: you can get by on entertainment, cheap food, booze and so on, but that won’t give you everything you need. It's not so useful to react as we do to immediate stressors. Expecting difficulties, and thinking through how you will respond beforehand is a strategy for success.
For example, we're 100% social, even men: social relationships are crucial for everything. Everyone needs someone they trust someone to talk to - do what it takes to get some meaningful support. Your kids need it, and so do you.
It's not a lottery.
People with loving families can keep going in tough times. They might look like the lucky ones who won the lottery, but it wasn't a hopeful one-off gamble: they're resilient because of the long-term investment in their maturity, emotional health and relationships. In other words, consistency is important and you need to keep showing up. You never know which times will turn into valued memories, so spread your bets and improve your chances. Pay attention to your children, and you'll notice how irreplaceable they are. They'll certainly remember it.
Being a good dad won't change the world, and you can't fix everything. But keep being there, and you will be irreplaceable to your kids, and the people you care about. That's enough of a challenge for most of us, and enough of an achievement.