I understand that
$$\begin{align} J = \sum F \Delta t &= \Delta p \\ \sum F &= \frac{\Delta p}{\Delta t} \\ &= \frac{mv_2 - mv_1}{\Delta t} \\ &= m \cdot \frac{\Delta v}{\Delta t} \\ &= ma \end{align}$$
$J$ is impulse, $p$ is momentum
However, by just looking at the equation
$$J = \sum F \Delta t$$
I seem to think that impluse is high if for same force, time is higher. But I think that's wrong? I think for a certain force, if I exert it in a short time theres a larger impluse? How can I then understand the above equation more intuitively without expanding it out?