Yes, it is considered normal and quite common for people to talk to themselves while thinking out loud, even if nobody else can hear them. This behavior is known as "private speech" or "self-talk." Many individuals engage in private speech as a way to clarify their thoughts, organize their ideas, solve problems, or reinforce learning.
Talking to oneself can serve various functions, such as improving focus, reducing stress, and enhancing cognitive processing. It can help individuals understand complex concepts, plan their actions, and work through emotions. In fact, some studies have shown that private speech can be especially helpful for children as they learn and develop their cognitive abilities.
As long as it is not disruptive to others or interfering with daily functioning, talking to oneself is generally considered a normal and healthy way to process information and navigate through thoughts and emotions. It is simply an external expression of an internal thought process.