It's worth noting that MMT went on to place sixth in Sherb's contest.
Another example? Me. My first contest was a co-author contest in 2016. My coauthor ended up flaking so I got disqualified. I tried again with a succubus contest a few years later and got shamed. It sucked.
Now? I finished sixth in EndMaster's third prompt contest (and was praised by him, it makes me warm inside still), placed third in a review competition, and placed as a finalist (fifth) in Sherb's Summer contest.
Plenty of noobs do excellently on their first try (Fabrikant) and some old hands fuck up every now and then, mods included. Let your fear drive you forward.