The list below are the main three stages of life during our lifetime.
The Teen Age - At this age, you have time and energy but you do not have money.
During this stage, you live under your parent's or guidance, of course, teens have one of the best times, during this stage, they develop their skills, IQ and in a fun way. While most teens spend their time on Video games which do improve their mental habits. As a teen, you have a lot of energy but you do not have money.
Working Age - You have money and energy but no time. You spend a lot of time working, and later on, start building a family.
The working stage is the most crucial stage of every human being, because if you do not plan your life very well then the last stage of your life will not be you expected. If you fail during the working stage then chances are high you will fail during the last age of your life too.
Here are some of the things you should do during this period before you even start building a family, you should have investments in different portfolios, then on a long while, you should build multiple streams of incomes, buy long term stocks or bonds which a unit is usually very cheap in every country. Then your midlife is set.
Old Age - The Stage you have time and money if you planned your life as we discussed above, but you do not have the energy.
What does this old age mean for all of us? It may be fun, we adapt to a new lifestyle as we age.
Staying physically fit by exercising every day before you get old can influence your old age energy, because of the health benefits of exercising, you tend to enjoy most of it at your old age if it's a part of you.