It's hard, but it does get better
I just took my almost 5 year old son to see the Mario movie. He was in a full Mario costume, moustache and all. He sat there enthralled for the whole thing (I really enjoyed it too, if you played Mario back in the day it's crammed with nostalgia).
We got some quick food on the way home, then bed time. We've moved up to chapter books at bed time so I'm reading him Charlie and the Chocolate factory, no matter how much I read him he wants more (sometimes that's an issue) but tonight 4 chapters were enough. I left him listening to funny bones on his yoto, entirely content with his lot in life, a big hug and impromptu "Daddy, I love you, this was the best day ever!!"
I also have a 19 month old daughter that sometimes is a bit of a struggle. It's not her fault at all, it's just the age, she's delightful sometimes but really, generally a pain in the ass who would rather be back in the womb. She gives me occasional glimpses of happiness and understanding or joy, but on the whole she's still constantly looking for and asking for mummy. She'll come round but it's not easy.
Having the 4 year old act like this is basically showing me the light at the end of the tunnel.
I know loads of parents who love to tell me "it doesn't get any easier" almost like they're displaying a badge of honour for their difficulty or sort of lack of enjoyment in parenthood (that seems sort of fake or tongue in cheek).
So here I am saying it absolutely does get easier
(At least if you're like me and struggle a bit with the baby/toddler phase but absolutely love the 3 year plus bit. If you love the baby/toddler phase then all power to you, I hope you're having a blast and let me tell you it only gets better)