B787 Captain reported First Officer display screens displayed AHRU R status message followed by EFIS/DISP Panel R; and WEATHER RADAR SYS L fault messages during cruise. Flight returned to departure airport.

Narrative

Approximately 2.5 hours into the flight the First Officer's (FO's) display screens started blinking off then on. I looked and there were no messages displayed. About 3 hours into the flight 'AHRU R' status message was displayed. A short time after that the message 'EFIS/DISP PANEL R' was displayed accompanied by the associated check list. We ran the check list. During all of this I sent Dispatch an ACARS message telling them that we had the status message and to notify Maintenance. Dispatch sent an ACARS message back which stated that Maintenance said it is just a status message and it is was OK to continue. During all of this we also got a 'WEATHER RADAR SYS L' message. All of this was happening just a few minutes before entering oceanic airspace. Having experienced this same issue before two years ago and what I experienced in dealing with this degraded mode and only having a few minutes before entering oceanic airspace as well as remnants of a storm out in the ocean and the weather associated with it and with multiple anomalies including a loss of one our radars I decided to turn back to ZZZ. At no time in the flight did we receive an ACARS message for a request to contact Maintenance thru SATCOM. Had I talked to Maintenance I still would have returned to ZZZ based on previous experience.Some considerations in my decision to return to ZZZ.Going across the ocean in this degraded mode was not something I was comfortable with. We had a degraded radar system; we lost a level of redundancy in multiple systems; we had weather out over the ocean that we may have had to deal with; changes in how the FO had to control his displays and some other considerations would have put the crew in an unsavory situation and definitely an even worse situation had any other issues popped up; not a good situation to be in. When I talked to Maintenance a few days after my issue two years prior after they fixed the airplane they stated to me there were a lot more issues with the airplane than were displayed or that we knew of in flight; in other words; it was worse than what we thought. The simple status message" that are generally small items was actually pretty serious in this case. I was led to believe what caused the 'AHRU R' failure was more serious than the actual failure itself. Although I don't remember the actual details of the failures and discrepancies 2 years ago other than the AHRU; I do remember seriousness of the problem. This really left an impression on me and was one of the reasons I decided to return to ZZZ. This is the way an experienced Captain is supposed to operate. Other airports such as ZZZ1; ZZZ2 were not suitable due to thunderstorms between us and the airports on the coast. ZZZ was the best suitable airport. So in the interest of safety I decided to return to ZZZ.I feel that flight deck wi-fi is a must so we can obtain and view weather on our iPads. If we had the ability to view current weather on our iPads that would have really helped in deciding which airport to divert to. I had to base my decision on photos on of weather on my iPad that were over 4 hours old. I did know there was still weather on the coast and I knew I did not want to divert to any of those airplanes since many other flights were dealing with this weather."