Poohbear - runs in the rain toughen you up, but more importantly they allow you the opportunity to bask in your achievement. Also, if you never run in adverse weather, it means that if the worse happens for your race, you aren't prepared for it.
Another undulating trail run yesterday - but thankfully a bit less muddy. Only doing short runs (5-7 miles) over the next few weeks to enjoy the feeling of running unpressured (although am thinking about the Stockley 10k in a fortnight as have never run a race at this distance - 10 miles is my shortest as I am not the fastest thing on 2 legs!).