So I've been reading Meditations by Marcus Aurelius and other sources about stoicism. The thing is that I worry about the never showing feelings, I know you can't let your emotions affect your decisions but can you ever obtain true happiness without letting your emotions affect you now and then?

So what is the pros and cons about it you have encountered? I'm not sure it for me so please help me clear a few thing up. Can you some how trigger it, like turn it on and off when needed?