To be happy, we focus on what we are thankful for - instead of the limitations due to the disease. Multiple family members have spent the majority of their lives in wheelchairs due to this disease. We have looked at the wheelchair as a tool that has allowed us to still 'live' our lives.
I write in a journal daily...focusing on the positives in our lives. I use positive music as a wonderful mood enhancer. I share in online communities, trying to help others who are dealing with this disease. All of these things allow me to focus on happiness, to focus on being thankful for every day we're alive and able to create new memories with our loved ones.