Fuel priming

[steplift20]

Hi guys and girls ok this is what happened
Went out to start my baby (1978 steplift 1988 150 mercury 2 stroke outboard) I pumped the bulb but it was very soft like no fuel making thru it did that for about 50 squeezes and no improvement So I said What should I do or look for but let me try to start the motor and see what happens ,,,,,,,, She started right up and kept running So what I thought that if the ball does not get hard there is no fuel, But she started right up Can someone give me an explanation So I know not to panic the next time that happens, oh and previously The ball always got hard Thanks for any info on this matter Thanks Joe