We've all had them, mine was today.
Packed the car very carefully, two diesel powered models - Stiletto with Taipan Tyro & Peacemaker with Sharma 2.5. The Ramrod was the Glow powered model.
Unpacked diesels and support gear, about to put the lines on where's the fuel??? Oh Fudge! at home.

Repacked them and got the Ramrod out. Fueled up and fly.... Too rich to fly anything but the Team race pattern.

After a cup of coffee & a chat more Ramrod time, retuned and flying nicely, when the muffler worked its way loose and after several more Team Race laps it drops off. Luckily the grass was short and our junior has sharp eyes.
Now muffler refitted - longer bolts & lock washers - Finally a decent tune and flies out the full tank uneventfully. Until I land & I notice the canopy has come loose.
Still your worst day flying is better than your beat day at work, and I took home all the models I left with and the repaired canopy was quick and easy to do.
Greg