I love having discussions with my friends about cosmology, physics and just the universe is general but can someone explain to me why ALL my friends tell me this way of thinking is just plain wrong. We were talking about whether or not we think the universe is infinite or not and I told them that if the universe is everything that exists, then by its own definition it must be infinite, otherwise it clearly isn't everything that exists. Secondly I said to them that if the universe isn't everything then the universe must be inside of something else which in turn is infinite, and likewise if that isn't infinite then that something must be inside of something etc. So even if that is true that must mean that a is inside b, b is inside c, c is inside d ... to infinity so whichever way you look at you always arrive at infinite. They told me that infinite regression like this is a paradox and basically it stems from the inability to ask or even think about different possibilities, we simply don't have the mental capacity to think of other possibilities. They said that if everything needs to be inside something else then nothing can exist as there can never be the first "thing" but I told them that this is ok with infinity because just as +infinity doesn't have a finish point, -infinity doesn't have a starting point so it just means that it has been happening forever. To be honest none of us really have a clue what we are talking about but as friends sometimes they frustrate me when they say I am wrong lol so I come here for some advice. It just seems that no matter how many layers you peel back, no matter what when if or how the final answer just seems to be infinite.