When looking at a map of the Macedonian Empire, it seems like Alexander took the hard route, as his empire almost exclusively spread Eastward, leaving Greece in the far West of a growing empire. Why did he not choose to expand in areas closest to Greece, such as the rest of the Balkans, but rather, keep conquering towards India?
You might find this reply interesting: "Why did Alexander the Great go east into Asia, instead of west and conquer Europe?" by /u/Iphikrates . It's in the "The Hellenistic period" section of the FAQ. (In the app, look for it about halfway down the page.)
But that's just a starting point, not to discourage more discussion, questions, info, or debate.