The "memory" of the markets means that previously important levels (like the high peaks in the price of assets) will remain later on. Of course, this effect might get weaker by time, but sometimes certain levels from years and years earlier retain their role as support or resistance levels. You probably noticed the previously mentioned swing highs and swing lows in the list and, of course, all-time highs and lows are also swing highs and lows by definition. This could shed more light on why those highs and lows are crucial in swing trading strategies.
Bots use the support (lower level) and resistance (upper levels) for their trades so identifying these can be helpful in setting your buy and sell orders.
Look at the chart for Pinkcoin, you can see it redefined new support levels (top blue section) around May 1 in the 560 satoshi range but the resistance level (top blue line) remained the same. Redefining the support levels higher is a good sign that the coin is getting ready to "breakout" and move higher.