Erik Erikson's theory outlines eight stages of psychosocial development, each presenting unique challenges and crises that lead to the acquisition of basic virtues essential for personal growth. Success in these stages, such as trust vs. mistrust and identity vs. role confusion, is crucial for developing a healthy ego and social relationships over a lifetime. The final stage, ego integrity vs. despair, reflects on life achievements, where successful resolution leads to wisdom, while failure can result in feelings of hopelessness and regret.