I feel like my child is an "unhappy baby". We were at a friend the other day and her baby was running in the walking ring laughing and shrieking with excitement and so happy. My little boy never does that

If I am not right next to him he will crawl after my crying. When he wakes up, he cries even more when he sees dh or I (as though we will just leave him there - which we have never done!!)
I know each baby communicates differently - but he is so serious all the time and just doesnt seem happy?!