Happy Four-Months-Old Day! I'm happy you are growing, and I think you are, too; you seem to think this whole helpless baby business is for the birds. I can tell that you are ready to get living.
You've been a finger-sucker for weeks now, but in the past month you have developed a clear preference for your right thumb. You are also ridiculously strong. You've been rolling front-to-back for a little over a month now, and this week you've learned how to roll back-to-front. You do not enjoy being on your back, and now that you can roll off of it, I doubt you'll ever lay and play with a mobile again.
You are enjoying (and demanding!) much more interaction. You smile, laugh, coo and giggle, and love having everyone pay attention to you.
The Bumbo has been a good thing for you, and you like to command the troops from your seat on high.
Maybe you're just channelling all the frustration around you, though. This has seriously been the longest, hottest summer ever. We've barely been able to set foot outside (except to go to the pool in the evenings when it's cooler) since May. Blech. Bring on September!