Last Friday I went for an anti clockwise flight round the Glasgow zone in a 6 mph north westerly and experienced some of the most uncomfortable turbulence I have felt in 30 years of flying.On the return to Strathaven I joined dead side at 1750 qfe for a 27 rt hand crosswind join to find the low level wind favoured an easterly landing and announced my intention to join cross wind for 09 and turned 180 to join the circuit dead side for 09.in the turn I suddenly found the aircraft turning in a spiral dive to the left (initial thought wow what the f**k .)I lost 200ft during this and did have a small brown trouser moment.On finals at 400 ft 1/2 mile out with full flaps and idle (all looking good) I suddenly went up 1000 ft a minute and just commenced a side slip when the bottom fell out the market and went back down 1000 ft a minute.I was stunned that in seemingly calm conditions we can be lulled into a false sense of security.lesson learnt is if my ex instructor has decided not to fly due to turbulence he felt then follow his lead and leave the aircraft in the hangar.No harm done this time but I learned something.