Tom found out that life on the road wasn't as easy as he thought it would be.
- Tom discovered that life on the road wasn't as easy as he thought it would be.
I heard that footprints of an abominable snowman were found in the Himalayan mountains.
- I heard that footprints of an abominable snowman have been discovered in the Himalayas.
... And then I discovered actually that NASA ...
... who made the series work. In particular, a physicist. He was the one who discovered ...