NB: This are my opinion and my idea; feel free to contribute; then dyor and trade and invest wisely
That is right. Know what coin you are holding will gives you the best result in the long term. That will works if you can find the profitable coins and as long as you can search with the right information, you can find not just one coins, but maybe you can get more coins for the investment in the long-term.
Perhaps, it would need more than a year before the price can increase higher, but it's not a problem because you don't want to sell if the price is not rising so high. You can hold for a long time, and you don't mind to see the price changing every time because you are sure that the project was very good and will grow in the future. And once the price reaches the highest price, then that is your time to sell the coin and make a lot of profit.