Parenting is by far the most difficult, stressful thing I've ever undertaken. My kids are mostly not too difficult, but they're very different nonetheless. My son is Mr. Compliant and is exactly the kind of kid that makes people think they must be rockstar parents. My daughter, on the other hand, routinely makes me feel like an ineffectual failure at parenting. I love her more than anything in the world, but she might well be costing me a few years of lifespan :).
One major problem, at least from my perspective, is managing the transfer of responsibility as a child progresses from toddler to adult. It's not like you throw them the keys at 18 and say 'good luck!'. So there is ongoing give-and-take, rules, negotiations, and extending trust. My kids are 10 and 12, which is an exciting time for sure. Puberty is a wild ride whether you're the victim or not :)
Haven't let her get a smartphone yet, but this is an ongoing battle. Because when she says 'but all my friends do!' she's not lying. I have to temper my fears and try to remember what it's like to be a kid. As an adult I had largely forgotten what it was like in middle school.
> Parenting is by far the most difficult, stressful thing I've ever undertaken.
From my observations, I don't think this can be overstated, at least from an American perspective. It is easily the single largest factor in my decision-making on this topic, and seems to be something which many people underestimate.
Edit: I guess I didn't word this very well. Please consider this comment in the context of my earlier one: https://news.ycombinator.com/item?id=34901931.