2017 was definitely unexpected. I assumed the % change since previous peak would have gone down each time as your theory would suggest instead of up nearly 3x as much. The interesting thing is that the number of bitcoins in circulation (currently only 18,375,312) has grown so slowly and steadily as it is designed to do. I'm curious how many bitcoins are lost forever in inaccessible wallets.
Apple stock has increased 100x in the past 15 years, but that doesn't mean it will increase 100x in the next 15 years (which would put its market cap at approximately 5x US GDP).