Nothing is guaranteed, although I understand what the OP is trying to say. As @mindrust already mentioned, past data doesn't predict the future. Yes, the historical data show that Bitcoin has been performing in approximately 4-year-old circles, but that alone cannot guarantee what's going to happen in the future. Moreover, we don't have enough data to safely say that this will also happen in 4, 8, 12 years, and so on. If we suppose that we had a history of 30-year-old data and identified that every circle runs every 4 years and the price surges to a new ATH every time, or close at least, then we could be more confident in what we could predict for the future.
I was completely disheartened when Bitcoin crashed in 2017/2018, and lost interest in cryptocurrencies. After I saw what capabilities it had, rising up to $20.000 again. in 2020, I was certain that I needed to get back on track.