If we FULLY KNEW everything that makes us tick, would we not see our day to day activity (except in the case of accidents) as foreordained to certain extent?
Putting it that way (use of terms such as "if" and "to certain extent" and "would we not see"), yes, absolutely.
But decisions are based on probabilities more than absolutes. There may have been a 98% chance that I'd wear the clothes I'm wearing today, but if so, there was always that 2% chance that I'd have somehow ended up wearing something else. I believe there are currents in the universe that we flow along with for the most part, but there are always those black swan events that make life interesting.
And speaking of making life interesting, if the premise is correct that there is barely any free will, if any at all, wouldn't that make the "ignorance is bliss" cliche' appropriate? Isn't it the fact, then, that we DON'T know what's going to happen, that makes life interesting for many?