Not Fade Away
I rode my first 200 in 2016, it was with my Audax friends. This meant a very leisurely pace, and a very pleasant long day in the saddle: 10 hours and 44 minutes of moving time, 14 hours in total.
Apparently it didn't scare me off, for I've done five subsequent double centuries since. Corona years were excluded.
Last year I rode two, a beautiful flat and fairly quick 200 in the Spreewald in April, and a more intense 226 km Rund Um Berlin in September. Rain for the first 60k, high speed for a long distance route throughout. What I've learnt is: fuel well. Then you won't Fade.