Any person would sell their stash at few 'x', what factors made you keep holding it?
experiencing 2 distinct bubbles (2013, 2017) is what did it.
in 2014, it was very easy to get pessimistic about bitcoin: merchant and consumer adoption was disappointing, nothing much exciting was happening in the development space, the price was bleeding and bleeding nonstop. there was a general feeling that, "maybe the naysayers were right, maybe it was tulip mania, maybe bitcoin is just a niche currency, maybe i should sell my coins."
fast forward to 2017, when i was holding
a lot less coins. that 2nd bubble showed me that bitcoin was here to stay, that mass adoption was an eventuality. and my depleted stash of coins taught me to hold onto them for dear life this time, instead of worrying about the sky falling in a bear market.
that's what it took for weak hands to become strong hands, in my case at least.