Your title, first sentence, paragraph, page, and chapter are your hooks to catch the reader. Make sure they are baited well. So, if you start with internal monologue, it had better be interesting, not just bland, random thoughts about how it's high up on the wherever. I realize that was just an example, but compare:
Bad: "It's so high up here," thought Sam as he climbed a tree.
OK: "It's so high up here," thought Sam from the claws of the giant
Better: "I can see the whole Shire," marveled Sam, then screamed as he began to fall.