Transaction fees, exchange spread, exchange fees, bank fees, currency conversion fees, card fees... Some of these to be counted twice, once you sell fiat for sats, then you sell sats for fiat to buy food. I used to dca and put all the money I earned from work in sats, but I was losing up to 30% of it in fees. In bear markets it can be soul crushing. I am a member of Mensa, but I honestly feel like a fool, a complete idiot.