[GaryH]

What are the realistic chances of growing a cherry tree/shrub from the seeds of the cherries that I have just eaten.

Once they have been washed, will anything happen when potted.

[Trillium]

Chances are good most of the pips will grow. However, what you get might not be what you expect if the pips variety was a hybrid. You could also have a problem of hardiness if the parent tree was grown in a warm, semi-tropic area rather than the UK.
If you want a tree, it'll take at least 10 yrs before it's a decent size and fruiting. You could try cordons which would possibly give fruit within 3-4 years.  If you have the space, consider it an interesting experiment.

[senrab_nhoj]

I was wondering how you could tell if a tree was cheery or sad

[DD.]

I was wondering how you could tell if a tree was cheery or sad

If it's a weeping willow - it's easy!

[gobs]

Easy! One has got a sour pip.