Those black beetles everyone saw roaming around TX in 2001
LOL Those were unreal! I stayed one night at the Super 8 in MAF and they were EVERYWHERE - on the sidewalks, on the wall, in your room. It was like a B horror movie.
Lots mentioned by many - I'll add a few...
Having had two occasions where I could chase for 4 weeks and having it be in 1992 and 1994.
Having only one week vacations and a ridge and then franticly chasing to get SOMETHING/ANYTHING on the last few days (1996 & 1997)
Have BIG days on the day that you fly back or on the day after you fly back (1995 & 1997 - and Jarrell was the next day and having a nowcaster who was ALL OVER that event and would have certainly mentioned the potential to me that morning)
Watching Supercells in NE OK from 40,000 feet as you fly back (1997 - actually it was kinda cool!)
Chasing alone.
The 55 mile an hour speed limit.
Backbuilding storms
Cold Fronts
Cold Fronts that won't stop plunging S
Chaser Interia ("must keep driving") - cost me the SC KS stuff on 25 May 1997 as I drove up I35 through Wellington, Harper, Anthony, and then down to Kiowa. Stopped and watch my first horseshoe vorts and the kept moving to the NW and N and ended up in Sawyer and saw NOTHING.
Hearing about tornadic storms up along the W Front and getting drawn N - and not having access to data (even a sfc map) to reinforce the notion that I was is where I wanted to be and keep me on my forecast (see Chaser Inertia above)
Pumping $10 gas (sucessfully!) in Arkansas City, KS in the dark in Bear's Cage wrapping raincurtains and with the sirens going off.
Almost running out of gas
Not knowing you're driving in "Drive" and NOT "Overdrive" for long enough to almost run out of gas.
Food Poisoning
Tossing one's cookies under mammatus and missing the ST Elmos Fire on my antenna
Mosquitos NE of LBB
Childress motel prices
but even with all the foregoing, the WORST one is:
Not being down there on years when I couldn't chase. :?