If you want to try to imagine this footage from Juno Beach would give you an idea.
I am sure there were other landings that got more reaction from the Germans than this shows.

https://www.youtube.com/watch?v=DV7mK0iT3P8

Imagine how many more men and equipment came ashore over the next few days and weeks and then months.

I need to read my uncles story again as he went ashore on D+ 3 or 4
I know the beach was so crowded that they did not land when planned and had to pull back out to sea and wait for the next high tide t get ashore. that was an experience in itself waiting on a bobbing landing craft for all those extra hours.

His story indicates how confusing everything was on the ground when they did get ashore as they were directed to several different locations before they finally were able to set up for refuelling and rearming Canadian planes. The planes returned to Britain every night until the end of June so they would not be on the ground if the Germans broke through.

I am sure those who were not there have no way of truly imagining what was happening to those who were in the middle of it.