Being a parent is hard. It's not hard in the way anything else is hard. You bring kids into the world and you do your best to take care of them, but you have to let them experience things and live their own lives. So yes, you get to feel the exuberance of that first job through their eyes again, and their wonder at things when they are little. And yes, you get to feel their new interests piqued in things, and watch them become, I don't know, whole people as they grow up and it's wonderful - but you also have to feel all their disappointments, and their losses, and their worry about their futures, and it's like reliving it all again all the time.
At the end of some days, I feel like I've lived six lives, all of them different. I'm exhausted, and sometimes I have to admit to myself that I'm not always happy at the end of a day. I try to be happy, because I feel like that's my number one thing to give my kids: positivity, I guess? Don't listen to me, I woke up tired today.