You're never absolutely sure what the picture is going to be and you know it's always possible that this bit or that could be out of place, or doesn't belong at all and that, as more and more pieces are added, you may have to re-arrange the pieces and toss some out altogether, even completely rebuilding whole sections.
And always there is the excitement and anticipation of getting closer and closer to the complete picture, never sure quite what it’s going to look like.
And then you realise your picture is just part of a much larger, more complex and astonishing one..
Contrast this with Creationism.
Given a jigsaw of pieces of evidence to put together, a creationist will start with an absolutely unshakeable conviction that it'll be a picture of a god. This is called 'faith'. This is the one thing which cannot be, under any conceivable circumstances, wrong. The picture must be of a god.
So, the pieces are first examined to see which must be discarded because they don't make a god - obviously they are there just to mislead and confuse and were probably planted just to test the 'faithful'. Not fooling us with wrong facts!
Then the rest are forced into place, being modified and changed to give a more or less acceptable fit, not worrying too much about the gaps and discontinuities. Pieces of sticking plaster can be used when the pieces won't join up properly. 'Misleading' bits can be cut off as required and whole areas can be left blank or coloured in later, because we know what they would be like if they were there. 'Faith' you see! The important thing is that they are making a picture of a god. If they do, they're in the right place; if not, they can be moved or thrown out.
Then, with a gleeful pride the Creationist can stand back and see, that, in dim lighting, if you squint hard and look at the right angle, there is that wonderful picture of a god! Only those without the right 'faith' could fail to see it.
Look at those arrogant, elitist scientists over there worrying about where that little piece should go. How many times have they changed their minds?
And they've still made the wrong picture! ROFL!