Is it really possible to 'Sell High and Buy Low' in this bull run?
First I sold some at 19600 hoping it will pull back before crossing 20k and I will buy back at 'LOW'. It never pulled back.
Then I sold some again at $25k milestone, hoping that it will pull back which never did. I then sold some at $25800 hoping it will pull back before going further. And again it never pulled back. BITCOIN is just going ATH after ATH.
BTC is setting new ATH every day, if not every hour

I stopped selling now

It's not like I am complaining, far from it! I am enjoying every bit of it. But how can we really follow the mantra of 'Sell High Buy Low'

Yes you can but with no so big difference in price for example today when the price is 28k then you bought again in 27300 then you already increase your holdings and earn profit. But if you are looking for big price difference that you can buy and sell then you should wait for correction before buying it.
There is no way you can easily find a good entry when you know that Bitcoin rally continue and you can't find a good entry and hard to predict price of Bitcoin .