No, it is not true that simply thinking about something will make it happen. The concept you are referring to is often called the "law of attraction" or "manifestation," which suggests that positive or negative thoughts can attract corresponding events into a person's life. However, there is no scientific evidence to support the idea that merely thinking about something will cause it to manifest in reality.
While positive thinking and visualization can have some psychological benefits, such as boosting confidence and motivation, they do not have a direct causal effect on external events. Real-life outcomes are influenced by a combination of factors, including our actions, external circumstances, and the decisions of others.
If you want to achieve a goal or make something happen, it usually requires active effort, planning, persistence, and sometimes a bit of luck. While a positive mindset can be helpful in staying focused and motivated, it is not a magic formula that will automatically bring your desires to fruition. Instead, taking practical steps and working towards your goals is more likely to lead to tangible results.