Back to basics
When the market drops, as it did early this year, it paid not to panic. If you had sold during the decline you would have missed the substantial gains of June, July and August. It was much easier to have remained calm while losing money in the stock market.
If you set things up right, your investing will require that you do nothing further except, perhaps, rebalance your holdings every so often to make sure you have the proportion of stocks and bonds that you really want.