While gardening, it is very important to tend to every aspect of the garden. You need to take care of the soil, you need to take care of the small plants and the big, you need to keep animals out, you need to take out weeds at regular intervals, you need to water the plants regularly, you need to plant new seeds.

If you neglect any one aspect, it will suffer and the entire garden will be affected adversely as a consequence.

Likewise, at the gym, you need to pay attention to all groups of muscles and design a holistic workout. Or, the neglected muscles suffer and then the entire body.

The products you build are no different. If you neglect some segments of users, then they fall to the wayside and eventually your entire user base suffers (as there are always users at the margin).

Organizations follow this too. Neglect one department and it will wither away, dragging other divisions with them.

And finally, your own life, where this is all too apparent.

What gets neglected, consciously or unconsciously, withers away. And this usually has a cascading adverse effect on even the areas that aren't actively neglected.

Be aware of what you're neglecting. And when it is necessary to do so, safeguard the other areas from the spillover adverse effects.