I think when you’re transitioning from being a people pleaser into a person with more boundaries it can feel so weird – it's hard to tell if you’re being mean or if you’re actually just respecting your own feelings, because you’re so used to putting other people's feelings first.
Maturity is realizing their lack of effort is their lack of interest in you, their lack of interaction is their lack of resonance with you, and their lack of response is your lack of importance to them.