I got caught like this once. If you checked the forecast and it was Ok then you have done all that was expected. You then did the right thing by sorting it out. You will probably enjoy the IMC but having done the IMC you will probably do the following.
Instead of heading away from cloud and hoping it will turn out OK, give your base field a radio call and ask them what the weather is like. If its pants ask them for the nearest clear aerodrome. If you can't reach the local field London Information will give you weather for any aerodrome. Most LARS services also have access to weather. If they can't help D&D will. You are not alone.
Thing is don't fly home expecting life to be OK then find you don't have fuel to make the alternate which is clear and was reachable when you originally noticed the problem.
Weather forecasts can be wrong.