If you happen to decide that it's not possible to be certain, does not mean it is nor is everyone else required to join you in your uncertainty.
You are correct MM. We can indeed, know for sure we are going to Heaven when we die. God is faithful, even when we fail Him. If some people don't have it, they are missing out on the joy God has most assuredly given to us. I am sorry if others have no assurance, but I promise you MM, I won't let it get me down. I have my assurance, others can have theirs. If you tell people about assurance 5,000 times, and they reject it, then it's on them.