Here's mine:
1. Torturous games part 1 - early deficits
I found myself still feeling so great being down "just 10", especially towards the end of the era in the 2011/12 and 2012/13 seasons.
In retrospect, it does seem like sheer nonchalance was the cause of quite a few of those.
I'm far too familiar with: "Down 10 points, nice effort guys. Keep going. There's still 3 quarters to go!"
2. Torturous games part 2 - blowing leads
On the other end of the spectrum, I've found myself being oh so scared when we have huge leads. Seems like 90% of them get blown, again seemingly due to them just not caring.
The most recent, and perhaps the most representative, was the epic "reverse blowout" against the Hawks. We were mashing and smashing the Hawks. Of course, Rondo's ACL might have remained intact if not for that game.
3. The mid-range shot
Yelp. An entire offense revolving around the worst shot in basketball.
The offense was 15, 16, 17 seconds of pounding the rock and standing and everyone else standing around watching, then 5, 6 seconds of hot potato. No off ball movement, less so without the traitor.
4. Rebounding
The lack thereof. Getting killed on the defensive boards is unbelievable. It sucks it sucks it sucks.
5. Scoring droughts
Incredible. Just a culmination of points 3 and 4. Which makes it suck even harder.
Of course there's good with the bad. Every point above has an endearing, memorable counterpoint and more.