First camping trip with the family - what did I forget

We're leaving Friday for a 2 night camping trip about 90 minutes away. Got the tent, sleeping bags, stove, cooler, food. Kids are 4 and 7. I feel like I'm forgetting something obvious but can't figure out what. Wife keeps reminding me to bring first aid stuff which is smart. What's the one thing every dad forgets on the first camping trip? Please tell me before we leave so I don't have to turn around halfway there.