it's gonna depend on the size of your work place really. hr isnt so much the group that is a resource for you the human. think of them like the IT dept that manages the human resource. if you've plainly stated your boundry to that person. "it's not your business what my mood is, if your uncomfortable with me not behaving in the excited mannor you want. that is a you problem". it's on your manager to ensure the other person respects that boundry. and if your manger doesnt do that, hr should definitely care because thats a problem. that said. it's far easier for everyone to just say "smile more, we're a family and we all behave the same way" in smaller org. and you'll have to decide if staying in a place that wont respect you boundries is healthy. my work pays me to complete specific things, not fill in someone's social circle because they need a trapped audiance to maintain friendships. i was lucky in my current org to have a manger who caught a situation like you describe happening to me and take zero nonsense from the other person. and now that i've worked with that expectation, with someone who would enforce that, i'm not willing to consider my persoanl life part of what the org is paying for.