Sorry to here of your loss grandpas are great to have and you will surely miss him, Mine died several years ago but I never forget as it was 3days before my 17 birthday anyway cheer up and try remembering the good time you spend with him.
This may be tasteless... But it's getting time for a lot of old people to be... Passing away...
Baby Boomers are starting to reach old age...
Sorry for your loss