My major fear is being always one step back behind the market and innovations, or being afraid to take a risk and buy an altcoin or do an action.
Numerous times I have skipped selling an altcoin on swap due to high transaction fees. Not this alts cost almost nothing, but those who made transactions, receive airdrops that cost a lost. Same is with NFT. A lot of people bought them for few dollars, but I have skipped that due to thinking they are useless. Now they cost many times more...