It's been over 4.5 years since my dad died. I feel like I'm through the grieving process in that I don't experience those same symptoms that accompanied me so strongly for the first two years. But you never replace a lost loved-one with anything or anyone. There should never be an attempt with such a thing. Sure, you can get married again or have another kid, find new friends or take up activity that takes up the time you used to spend with someone else. None of that is bad, and most of it is good, but none of that can actually fabricate the person that is now gone.
So it's ok to miss, and sometimes those misses are hard ones, but it's ok to do it because you can't get that person back.
That all said, I do know that I'll see my dad again some day because he put his faith in Christ before he died. So sometimes, with the heart of the little girl that he pushed on the swing at the local city park, I ask God to tell my dad that I love him.
I know you can't really communicate with people in heaven, and I know that our relationships will be different with one another when we get there, but I would just like to think, if not pretend, that God would do such a thing.
Maybe it could just be a little extra joy that day, if extra is possible in that perfect and most excellent place. Maybe it could be just a little more...joyful, a little more warmth, that would say to him "I'm doing ok, but I'm so excited to see you someday, and in the grand scheme of things, it will be someday soon."
Like an amputee who misses their arm or a blind person who misses their sight, I have both learned to be ok despite this loss, and I have learned that some things, and some people, are just ok to miss no matter how ok you are.