Lessons from a stock I intended to hold long-term but ended up short-term trading

There was a case where I found a good stock with strong fundamentals, intending to hold it long-term for dividends. But when the price started to run, I couldn't resist and decided to short-term trade a bit. I ended up selling too early when it dipped, and then it continued to run without ever coming back for me to buy again. I regret missing out on many multiples of long-term gains, all because of my own itchy hands.