Text messages

I am new to iOS, less than a year. I technically have 2 questions in here. Someone please help! So I know the last conversation you have in your text messages opens when you leave it and click back on it. I just read that when u force close it that it should go back to the main list of all your text messages when you open it again. So I swipe up and swipe it away until no app is open. Is that force closing it? And if so, does anyone know why, after I force close the app, it still goes back to my last conversation?