These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Crazy Stupid Love
Designated Hero: Robbie is presented by the film as a plucky, charming kid who never gives up on his love of his babysitter, even when the odds are stacked against him. Unfortunately, his love quest involves constantly following the girl around badgering her to date him, staging elaborate displays of affection that make her a laughing stock, acting like she's cheating on him when he finds out she likes someone else, and even turning his valedictorian speech into a passive agressive rant about not believing in love anymore because a crush turned him down. Add in the fact that this comes to light because she caught him masterbating to her, which he has absolutely no embarrassment about, and how he truly seems to believe he's entitled to a relationship with her because he's "nice", and many people end up seeing him as a Creepy ChildStalker with a Crush. The fact that he never learns a lesson about respecting people's wishes and not making them feel uncomfortable, and instead gets rewarded for his behaviour with nude photographs of his crush makes it even harder to root for him.
Fridge Logic: Liz is presumably a very close friend of Hannah's. Has she never met Cal or seen pictures of him, enough to recognize that he's the guy Jacob is with at the bar? Not only that, but it appears that Hannah goes to the bar fairly often, yet never once ran into her father there.
Also, do none of these women that Jacob sleeps with then never calls again ever return to the bar?
Hannah pretty much puts her social life on hold in order to study for the bar exam. She stops going out the same time Cal starts frequenting the bar. And Liz might only go to that bar with Hannah, rather than by herself.
A couple were actually blocking Cal clearly from Liz' view.
Harsher in Hindsight: Robbie cites Ashton Kutcher and Demi Moore as an example of a younger man/older woman relationship that's gone strong. Cut to a year after the film's release...
Hate Dumb: In-universe. Hannah's friend's reason for disliking her fiance is solely that he's nerdy and boring. Jacob is hot and fashionable so the fact that he's a womanizer is a non-issue with her.