我喜欢这个。( I like this ) 我喜欢安静。 ( I love being quiet ) 你很快乐吗？ ( Are you happy? ) 很 = very, in this context, so 你很快乐吗？ = Are you very happy?. 你的一生很快乐吗？ sounds more like 'Are you happy in your entire life?'; I would like to say “你的生活快乐吗？”

Thank you very much, Lucie! :)

I love being quiet:我喜欢安静。“安” this single word have many different means, like the word "安全", safety; "安心", means don't worry, be relieved. Here you mean "安静".