I don't think that I will be using bitcoin for next 20 years as my goal is not to hold it that long instead will prefer to collect as many coins as possible at a moment and will sell all my bitcoin in next 5 years whatever price it would be holding and then say bye bye to bitcoins.
Yah, same as mine. I think there will be another cryptocurrency.
BTW, it's no matter if we discuss about this hot question:
Bitcoin hits 10000: I will buy things such as best cellphones, best computer, gaming PC, playstation,... and invest in bigger deal
Bitcoin hits 100000: I might be 'rich' in my country. I can buy a small house in my hometown and pay for my tuition fees.
Bitcoin hits 1000000: I am real rich, I will buy a big house for myself and take a rest time (of course I shouldn't stop my bussiness career).