Diki good post ....BUT Timing & keeping rhythm is more then just practice. I see people on the Dance floor every night just moving around with NO IDEA or conception of the tempo & their timing to dance to the music....its as if I blindfolded you & spun you around 10 x then said OK NOW DANCE!! they just aimlessly move around. I know people who have paid thousands in ballroom dance lessons & can't keep dancing to the tempo no matter what? The waltz being the worst example of this along with any other type of dance....that is the same scenario when I hear some people play and cannot keep time. Now practice can help some people if taught correctly BUT, then again some people & through NO Fault of their own JUST DONT HAVE RYTHYM INSIDE them!!......its not their fault its the way they were born.
But I commend anyone who really tries to improve their chops & enjoys themselves doing it. We're not all the same.