Not sure if Tom used gravel. That was my idea. It sounds like your truck is liking being started more often. Sometimes jumping out of gear can be caused by worn gears. It could also be old dirty trans oil that won't let it go fully into gear, dirty sticky slider not working freely. Or bent shifter forks that don't let it shift completely, not getting the full throw.

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain