That is a very shallow conception of Heaven that your friend has then... how can anyone say whether the state of your consciousness in an afterlife even perceives 'boredom'? Isn't boredom an instinctive survival mechanism like hunger and fear anyway? Would something like that even be relevant in any higher plane of existence? Wanting to cease existing is like Nirvana and Destrudo - principles that really makes no sense at all. Those theories are mired in philosophy of existentialism and physicality - sure if afterlife is anything like life as we know it now, then certainly you would get 'tired' or 'bored' of it over time. But would time even exist in a 'place' like Heaven, and more importantly, would an existence that we cannot even conceive of necessarily ever become 'boring'? The same thing goes for fear - who is to say you feel fear in Heaven? Most people think of it as wayy too much like the embodied existence we experience now. I'd bet it isn't.