After V1 if you abort the T/O then the chance is high that you end up in the mud
It's also worth reminding ourselves that on a limiting runway the reverse is also true. If you are too "go minded" and decide to continue at a speed below V1 you will not have enough runway left to accelerate to VR and get airbourne before running out of tarmac. Not a nice prospect either.
Pretty good advice but just to add some shades to this and your decision making. The data shows that even trying to stop succesfully, without damage, at speeds above 100kts is not reliably safe.
In other words 5% of these result in aircraft off the runway. As the abort speed goes up so does the error rate. This however should not imply that at speeds +5 above V1 you will have a 100% chance of failure, but you certainly will be at the very high end.
This also suggests that V1 should be considered a flight decision speed alone.