It's important to celebrate our elders and their achievements and their value to society.
There have been lots of studies and trials on being healthy in later years, particularly emotional well-being as that has a definite impact on your physical well-being.
Yes it is possible to change your ways and improve your life by overcoming those things that are annoying you, ( I am not talking medical or physical things - I'll leave those things for the doctors and medical professionals)
YES - you can learn to overcome stresses, difficult situations, bad habits. Scientists have done thousands of trials and brain scans, and the brain is pliable i.e. plasticity of the brain cells is real.