Got started on 4th edition in 1995, got back into it with 7th edition in 2001, got back into it again, competitively this time, with core set 2021.
Ex-hacker, ex-semi-pro poker player, now lawyer practicing art & entertainment law, criminal defense, and civil litigation.
My "fearless magical inventory" of holes I'm working on plugging:
1) I do not playtest enough with sideboard and often do not generally know how to sideboard correctly in specific matchups. I often over-sideboard.
2) When winning in a game, I sometimes get over-confident and allow myself to play into my opponent’s outs, whether that be overextending or using my removal needlessly.
3) I forget most of the cards I pass in Limited right after I pass them.
4) I sometimes tell myself that my bad play didn’t matter, because I would have lost anyway.
5) I sometimes tap my mana wrong and end up unable to cast a spell.
6) I do not spend enough time examining all the possible blocks in a combat and sometimes only take into account the one I would do, which is not always the correct one.
7) I sometimes over-value specific cards in play and do not play around removal.
8) I sometimes play the creatures in my hand from most to least powerful, allowing my opponent’s removal the optimal efficiency.