I remember purchasing my first domain name in the year 2008. It was specifically meant for personal use. Later on realized that flipping domains could make you a fortune.
2012, if I can recollect. It was for a personal blog. Only around October 2016, when I sold that blog, did I realise that there is something called as Domain Trade!!!
2012, bought few domains for sell without even the slightest understanding of sales or domains
These were seo-promotion.biz, world-games.org and two IDN names. When came expire date I deleted all names and thought - it's a bad bad business and I cannot make money on it.
A typical mistake of a person who is looking for the cause of problems in something, but not in himself (in this case - the lack of market understanding, which names pick up, who is my end user etc).