Greatness starts in the mind, but it doesn't stay there — it has to be given a voice and a direction to actually materialize. Thoughts are things, they say, but until they are given voice, plan, and pursuit, they remain intangible. Thinking big is the beginning; no one becomes big while thinking small. But without talking, walking, and working hard toward that big thought, it will amount to nothing.
When the thoughts of your mind are strong enough to force themselves through your mouth, hands, and legs, they have started accomplishing themselves, and nothing can stop them. When you only think and don't talk, no one will know what you're thinking. When you talk without action, no one will see what you're talking about. You show people your thought by what you say and do.
Think, talk, walk, and work are the steps on the ladder to success. Anyone out of joint on any one of them will find the climb difficult. Words give voice to thoughts; actions give signs to words — they always work together. Whatever you think of doing, say that you are doing it, and be seen doing it.