I finally started getting stronger in the gym when I stopped going to failure on everything. I got in the best endurance shape by going on a steady comfortable pace for progressively longer periods of time.

Harder is not always better.

One of my favorite styles of weight training is volume based. The premise starts with something like I need 10 reps of a certain weight, but it doesn't matter how many sets it takes to get there. Each set ends if I cannot do another perfect rep. If I can't do a single perfect rep, then the exercise ends and I move on to the next thing. By requiring the rep to be perfect, it naturally keeps you from going to failure and lowers chance of injury.

There's more to it like how to pick the weight, etc... but the perfect rep piece I really enjoyed.

I noticed the same.

Also late to the party, but creatine is the body and more importantly the brains friend too.