Done a few but never one that I decided to do and prepared for. Just got out on the bike and rode till I realised I was near the metric or over the metric and still had plenty of energy left to do 100 miles.

But days like that that are few and far between. Weather always seems to get in the way so I do organised rides---but do them on my own. Then as I have paid for the ride I will continue with the ride no matter how wet or windy the ride is going to be.