One of the dumbest cycling things I've done is..

[numbnuts]

I lost my keys on the 2nd June, luckily I have KeyCover insurance just a few keys so it won't cost much. Tried to get a key for my Abus D-Lock, they said they could not match it with the key code so had to buy a new lock.
Kryptonite in the USA, but they did the key for $3 = £2 so well pleased
the rest of the keys came to £24 so a total bill £91.82, good job I had insurance.

 

[Silver Fox]

Cycle round Delamere without using insect repellent, i'm sporting some impressive bites today.

 

[Andrew_P]

I have ridden in to work and forgotten the keys to open up, 30 mile round trip and drive back in.. Only done it once mind, I now have a hiding place for the spare set.

 

[colly]

Daftest thing I did?
One Sunday I went for an early morning ride. Very early. On the far side of Selby from Leeds, so about 30 miles from home. I got puncture.
Small irritation? No. BIG irritation. Tyre levers I had. Pump I had. Spanners I had. Even latex gloves and a cloth. Repair kit and spare tubes I didn't have
The previous evening whilst checking the bike over and making sure I had all my stuff I managed to leave all my spare tubes and the repair kit on my work bench.
It was still early, about 6.00, far too early to risk calling Mrs Colly on a Sunday morning. What to do ?
Well, set off walking. Maybe an hour later and finally back on roads more than 10ft wide some very kind soul ( a cyclist naturally) stopped and let me use their repair kit.

 

[HovR]

Depending on the quality of the combination lock, they can be surprisingly easy to break in to without tools. When a friend forgot the combination to his lock it took me about 20 seconds to unlock it for him.

I just always leave me locks in the locked position. That way you need a key to open them before locking your bike up, so you can't lock your bike up only to return and find you have no key to unlock it with!

 

[Sandra6]

I always leave the key in the lock, apart from when it falls off into the bottom of the bag and I don't realise!
Fortunately I did realise before I locked the bike to the railings outside the gym, and they were kind enough to let me bring my bike inside and leave it where I could see it.