You can't hold spot positions, and with contracts you always want to leverage more until liquidation, honestly it's not that you're not smart, it's that you haven't left yourself room to breathe in your positions. My current "plain language version" for myself is: treat the worst-case scenario as if it will happen, and only take positions that I wouldn't lose sleep over even if they do. When I want to go all-in, I write that impulse into my rules, like buying in three parts, selling in three parts—if I get itchy, I can only follow the steps, no impulsive decisions on the spot.

Recently, hardware wallets are still out of stock, and there are especially many phishing links, which also remind me not to tighten my positions too much: when the position is tight, people get anxious, and the more anxious they are, the easier it is to click the wrong link or sign the wrong authorization. Anyway, I now prefer to earn a little less, but keep a "breathing room" in my positions—it's really lifesaving at critical moments. That previous "breathing room" phrase applies just as well here, leaving some space for myself.