Bitcoin is a great coin that is way more bigger than the other coin, bitcoin is special I see it as world currency.
When investing on Bitcoin all we should bear in mind is that, this coin will always become better and bigger so when investing don't wait for it to come down in price before investing because that may never happen instead it will keep going up.
You are right, Bitcoin will keep growing gaining more adoption (though there's no guarantees) but base on how things is going we all believe so , . But during the journey they would surely be up and down movement due to volatility. Investing in Bitcoin is just the right call , this time around procastinating won't do anyone any good , because now alot of people are complaining that bitcoin is too expensive for them that they will start accumulating when Bitcoin price experience a massive dip which may not happen. And the funny thing is that in the future Bitcoin will tend to increase in value and get to a point of being more expensive. And same thing happens when Bitcoin hit the price range of $10k alot people where waiting for it to dip more before buying but now Bitcoin is far from such price and the chances of it falling back that price is damn loww.
I believe that these should be your concern now that price movement or been too optimistic that bitcoin would only go up than down, yeah there are also such possibilities but I prefer not to talk about those, but one thign you must remember is the only way to prepare for up is to have more bitcoin
Being optimistic ain't bad but still you are right, the best way to prepare for the up is to have alot of Bitcoin stashed, because even though a massive increase in prices in market takes place without you having much Bitcoin. You will only endup with less profits due to the small quantities you have stashed, so to avoid such scenario is to keep purchasing.