The Ideal Holiday Length
Day 1-2: Official Walk of Shame. Especially if in a country where the language isn't your first. Though you enjoy getting your bearings and wandering around lost, it takes a while to remember verb conjugations and vocabulary other than the basics so when you interact with other people is tricky. Depending on where you are the locals might not be as accommodating and their impatience with you stumbling over your words could be a slight blow to self-esteem.
Day 3-5: You've relaxed now, your languages skills have improved and you have a general sense of direction so you don't spend half the daylight hours lost and hungry. You explore, interact, learn, enjoy. Your confidence has returned. Tourists might even mistake you for a local and ask you for directions. You can give them!
Day 5-9: Practically a local now - you're speaking the language, thinking in the language! You've made friends, people recognize you in the street and call out your name to say hello. The lady at the cafe or bakery remembers you and smiles welcoming when you come in to order. This is nice!
Day 10-11: You've done most of your exploring and adventuring and your clothes reflect this. As a minimalist light packer all your clothes are dirty by now and though you've washed them in the bathroom sink bath soap doesn't work as good on fabric as it does on skin. You start to long for the comforts of home.
Day 11: Ahhh! 10 days of exploring a new place, the life! You're okay going home now...or onto the next adventure, as long as there's a washing machine on the way there.