You can invest in BTC, whenever you have the money and you will be happy to hodl BTC because if you miss this season bear run base on, you don't have the money to buy BTC, you can prepare yourself against next bear season which is what make many people to value BTC hodling than other cryptocurrencies.
Why do you think we should wait until there is a bear market before we invest? Bitcoin investment shouldn’t be seasonal, you don’t have to wait until there is a bear market before you make an investment. If you have money, you can make your investment at any moment, just make use of the DCA strategy to accumulate your bitcoin. And whenever there is a dip in the market, if you have extra money with you at that particular time, you can just take advantage and increase your holding. But don’t wait until there is a dip before investing in bitcoin, because no matter how bitcoin dips, lots of people will keep on waiting for it to drop more and won’t invest.