Leo understands the fact that others do not have a mind of their own, that it's essentially ONE MIND who rules them all. Now, you can associate this ONE MIND with the term MY MIND, since you ARE IT. So, he understands solipsism as ONE MIND who essentially is alone and only interacts with ITSELF - in the sense that everybody is just a figment of your own imagination and is ruled by YOUR MIND. That is correct. Now the problem in Leo's thinking is that he thinks he will live through others point of view (as consciousness inhabiting ALL the avatars - that is all the people who've lived and all the people who will live). He thinks this dream called reality is a shared dream between multiple instances of consciousness (HIMSELF) being through each and every one of the human avatars. This is his idea of infinity. But thinking it has to be like this is false. Infinity does not have to manifest itself it its entirety, by experiencing all the possibilities from within this dream (this universe). NO!  You can very easily be the only conscious experience - the one you are having through this avatar. In the sense that Consciousness (YOU) never have been through other avatars present in your life, never will be. This means that other people are essentially deterministic robots, there's nobody in there who feels pain for example. They are not having a conscious experience: seeing, hearing, feeling, thinking. They just behave like they're alive because you imagined them to be this way. You (as consciousness) will never experience the world through their skin, through their point of view.  Infinity does not have to manifest itself it its entirety, by experiencing all the possibilities from within this dream (this universe). NO! This universe was born when you came to into life and it will end when you die. ALL OF IT. It only exists in your mind. The past never took place. Nothing happens outside of your visual field, it doesnt have to. Nobody feels pain but you. Think of it like the game Grand Theft Auto, the world is being generated as you walk by. Nothing exists and nothing is happening outside of your field of vision.