Yes that's effectively what happens around resistance levels. Milestones may be psychological resistance levels. People may have common and similar milestone targets that they all want to sell at (every 1,000, 5,000, 10,000 etc..) ..there is a sell off until more new buyers come in and have an opposite reaction of seeing BTC hit a milestone target and not wanting to continue to miss out.

Yes trading is difficult and it's probably better to just be a very long term holder. I'm sure many people who got BTC when they were 5 cents sold them off when they were over a dollar and even more sold when they were tens of dollars .. it's probably better for people to forget they even have Bitcoin on their computer and remember years later.