Really today with my age factor (59) and other stuff just being better than before is success to me. For instance I am known for lengthy hubs. If I can keep them in that golden area for length I feel I am successful. If I do not forget to water the garden timely (I only have to water once a month) then I am successful. If I can keep my food budget less than the budget I am successful.
Overall if I am able to accomplish any goal I set for myself, even though not all the objectives are accomplished, then I feel I am successful and do reward myself someway and somehow.
Happiness is a different subject. I am researching that this month with an open mind between contrasting ideas. For now it is reading the World Book of Happiness by Leo Bormans, The Happiness Trap by Dr Russ Harris, and then head to library and internet. I will have a better idea after that :)