The market is cyclical. There is always the correction following the growth and the growth following the correction. The growth never lasts forever! Dont buy on peak. The drastic surge of the rate doesnt mean, that the growth will continue.
Buying on a peak is one of most common used mistakes in a crypto-trading, especially if you're a newbie. So, his tips could help a lot more trader soon. I hope they'll come here and read every essentials in trading you have.
I am not actually a trader, I have tried. Sometimes I loss profit, sometimes there's a gain. Well, just don't be greedy, like what the OP said. A gain will still be a gain, even if it small.