Introduction. The aim of the research is to analyze the essence of the notion "intellect" and to determine which intellectual abilities are the most important in the achievement of an individual's successfulness in the process of lifelong learning. The tasks of the research are 1) to conduct the theoretical analysis of the scientific literature on the given problem; 2) to work out recommendations for successful individual's lifelong learning. Methods. The method of the research is the scientific analysis of theoretical literature on the given problem. First, general definitions of the intellect are presented. Then more detailed definitions are studied, which underlie certain theoretical approaches. Results. The authors of the article conclude that an individual's intellect is an active component of forming the environment offering him/her the possibility to react flexibly to challenges and situations occurring in the contemporary word. This efficient adequate adaptation, forming and choosing the appropriate environment includes the process of lifelong learning which starts since infancy and continues during the whole human life. Discussion. It is confirmed that in order to use intellectual abilities to learn in an optimal way, an individual should have the possibility to adapt efficiently his/her own particular learning approach (learning style) to the environment by forming or choosing them. Conclusion. The ability to learn and the ability to adapt efficiently to environmental changes are the most important and significant factors of human intellect determining an individual's successfulness in the process of lifelong learning. © 2017.