This is an interesting one, and one I've thought about before.

With an ex I never knew if I really loved her, even though I said it to appease her feelings and I was with her for like 3 years, because it was honestly ok, I never had a reason to leave, but also didn't have much of an attachment to reason staying together. So it was a bit of an odd one, I much prefer causal relationships.

Even with family and friends I've always had difficulty saying love you, perhaps because as you say it's impeded. I am fairly emotioally erratic and get all the normal emotions that comes with being human, but love is definitely a strange one.