Try it before you buy it

So I recently watched a video of Calum Von Moger grocery shopping, and he said something that rang in my ears. Tri it before you bi it. He said this while pointing to his triceps first, then biceps. It made perfect sense. Most people don't realize that your triceps make up 2/3 of your arm size. Most people also don't realize that their tri's are usually lacking. So from now on, start with tri's while you have the energy. Then do your bi's. Tri it before you bi it! You'll definitely notice a difference!