As long as you are investing with your spare cash, your worries should go away. I'm a long term holder of BTC and have no desire to trade it frequently, hence, I don't get bogged down with its daily price fluctuation. At this moment, there are only less than 1% (probably much less than 0.5%) of the global populace owning or trading BTC and other cryptos so we are a long way from seeing a bubble forming. Just my two cents.